Patent Publication Number: US-8968094-B2

Title: Power management apparatus, and method of providing game contents

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a power management apparatus, and a method of providing game contents. 
     2. Description of the Related Art 
     In recent years, a technology called smart grid has been gaining attention. The smart grid is a technological framework to realize efficient power usage by constructing a new transmission network having a communication channel along with the transmission network and using this intelligent transmission network. The background idea of the smart grid is to realize efficient management of the amount of power use, swift handling of an incident when such an incident occurs, remote control of the amount of power use, distributed power generation using power generation facilities outside the control of a power company, or charging management of an electric vehicle. Particularly, effective utilization of in-house power generating stations using renewable energy by ordinary households or operators other than power companies and charging management of various electric vehicles typically including electric cars have been attracting considerable attention. Incidentally, renewable energy is energy generated without using fossil fuel. 
     Power generated by ordinary households or operators other than power companies is used by power generation operators. Remaining power after use by the power generation operators is currently purchased by power companies. However, purchasing power supplied from power generation facilities outside the control of a power company is a heavy burden to the power company. For example, amount of power supplied from photovoltaic power generation facilities depends on the weather. Moreover, amount of power supplied from in-house power generating stations of ordinary households depends on power use of ordinary households that largely changes day by day. Thus, it is difficult for power companies to receive stable power supply from power generation facilities outside the control of power companies. For the above reason, it may become difficult for power companies to purchase power in the future. 
     Thus, a home battery initiative that uses power generated by power generation facilities outside the control of power companies after temporarily storing the power in batteries has recently been gaining attention. For example, a method of using power generated by photovoltaic power generation facilities by storing such power in batteries and making up for shortages in the night or when the weather is bad is considered. Furthermore, a method of limiting amount of power received from a power company in accordance with the battery storage amount or using power stored in batteries in the daytime when power rates are higher by storing power, in batteries, supplied by a power company in the night when power rates are lower are considered. Also, batteries can store power as DC, which makes DC/AC conversion or AC/DC conversion during transmission unnecessary so that losses during conversion can be reduced. 
     Thus, various expectations regarding power management mingle with one another amid the smart grid initiative. To realize such power management, the smart grid initiative is premised on having a communication channel along with a transmission network. That is, exchanging information about power management by using this intelligent transmission network is assumed (see JP-A-2002-354560, for example). However, in a region where a communication infrastructure is already built, instead of using a transmission network as a communication channel, information about power management may be exchanged by using a network constructed by the deployed communication infrastructure. That is, what is important in the smart grid initiative is how to efficiently manage power generation facilities and storage facilities that are not uniformly managed. 
     SUMMARY OF THE INVENTION 
     However, to realize the smart grid initiative as described above at home, various investments have to be made. Presently, there are not sufficient incentives to introduce the smart grid. 
     In light of the foregoing, it is desirable to provide a power management apparatus, and a method of providing game contents, which enable to take eco-friendly actions such as power management and power reduction while having fun doing so. 
     According to an embodiment of the present invention, there is provided a power management apparatus which includes a managed appliance registering unit carrying out authentication on an electronic appliance connected to a power network and registering an electronic appliance for which the authentication has succeeded as a managed appliance, a managed appliance information acquiring unit acquiring, from the managed appliance, as managed appliance information, at least any of appliance information including identification information that is unique to the electronic appliance, information indicating an operation state of the electronic appliance, information indicating an usage state of the electronic appliance and power information of the electronic appliance, a database storing the managed appliance information, and a game service providing unit providing, to the electronic appliance, a service using game contents whose theme is power. The game service providing unit includes a game control unit controlling execution of the game contents, a real world constructing unit constructing a setting of a game reflecting a real-world environment, based on the managed appliance information stored in the database, and a virtual world constructing unit constructing a setting of the game reflecting a virtual environment, based on a setting set in advance in the game contents. The game control unit is operable to initialize the game contents by combining the setting of the game constructed by the real world constructing unit and the setting of the game constructed by the virtual world constructing unit. 
     Position information indicating a location of the electronic appliance may be described in the database. The real world constructing unit may be operable to arrange an object corresponding to the electronic appliance registered as the managed appliance in a game stage based on the position information. 
     The game control unit may be operable, when an object corresponding to the electronic appliance is selected, to display on a display screen on which the game contents are displayed any of the appliance information of the electronic appliance corresponding to the selected object, the information indicating an operation state, the information indicating an usage state and the power information. 
     The power management apparatus may further include a control unit controlling operation of the managed appliance and supplying of power to the managed appliance. A result application mode of applying a game result of the game contents to the electronic appliance in a real world may be set in the game contents. The control unit may be operable, when there is a notification from the game control unit indicating that the result application mode is carried out, to reflect a result of the game to an actual electronic appliance. 
     The game service providing unit may provide the service using game contents while acting in concert with a game service providing server provided outside the power management apparatus. 
     According to another embodiment of the present invention, there is provided a method of providing game contents, which includes the steps of carrying out authentication on an electronic appliance connected to a power network and registering an electronic appliance for which the authentication has succeeded as a managed appliance, acquiring, from the managed appliance, as managed appliance information, at least any of appliance information including identification information that is unique to the electronic appliance, information indicating an operation state of the electronic appliance, information indicating an usage state of the electronic appliance and power information of the electronic appliance, and providing, to the electronic appliance, a service using game contents whose theme is power. The step of providing further includes the steps of constructing a setting of a game reflecting a real-world environment by referring to a database in which the managed appliance information is stored, and constructing a setting of the game reflecting a virtual environment, based on a setting set in advance in the game contents. The game contents are initialized by combining the setting of the game constructed in the step of constructing a setting of a game reflecting a real-world environment and the setting of the game constructed in the step of constructing a setting of the game reflecting a virtual environment. 
     According to the embodiments of the present invention described above, it is possible to take eco-friendly actions such as power management and power reduction while having fun doing so. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram useful in explaining an overview of a power management system according to an embodiment of the present invention; 
         FIG. 2  is a diagram useful in explaining the overall configuration of a managed block; 
         FIG. 3  is a diagram useful in explaining a communication network in a local power management system; 
         FIG. 4  is a diagram useful in explaining a system configuration that is centered on a power management apparatus; 
         FIG. 5  is a diagram useful in explaining specific examples of external servers; 
         FIG. 6  is a diagram useful in explaining one function of a system management server; 
         FIG. 7  is a diagram useful in explaining the functional configuration of a power management apparatus according to an embodiment of the present invention; 
         FIG. 8  is a diagram useful in explaining the detailed functional configuration of an information management unit; 
         FIG. 9  is a table useful in explaining the detailed functional configuration of the information management unit; 
         FIG. 10  is a diagram useful in explaining the content displayed on a display unit; 
         FIG. 11  is a diagram useful in explaining the content displayed on the display unit; 
         FIG. 12  is a diagram useful in explaining the content displayed on the display unit; 
         FIG. 13  is a diagram useful in explaining the content displayed on the display unit; 
         FIG. 14  is a graph useful in explaining a time-series pattern of power consumption; 
         FIG. 15  is a graph useful in explaining a time-series pattern of power consumption; 
         FIG. 16  is a diagram useful in explaining a method of concealing a power consumption pattern; 
         FIG. 17  is a diagram useful in explaining a method of concealing a power consumption pattern; 
         FIG. 18  is a diagram useful in explaining a method of concealing a power consumption pattern; 
         FIG. 19  is a diagram useful in explaining various control implemented by the power management apparatus; 
         FIG. 20  is a diagram useful in explaining various information managed by the power management apparatus; 
         FIG. 21  is a table showing combinations of communication means, authentication means, and control over supplying of power in accordance with an outlet type and a connected appliance type; 
         FIG. 22  is a block diagram showing the configuration of an appliance management unit; 
         FIG. 23  is a block diagram showing the configuration of a managed appliance registering unit; 
         FIG. 24  is a block diagram showing the configuration of an information tampering detecting unit; 
         FIG. 25  is a block diagram showing the configuration of an information analyzing unit; 
         FIG. 26  is a block diagram showing the configuration of a control-compliant appliance; 
         FIG. 27  is a block diagram showing the configuration of a control unit of the control-compliant appliance; 
         FIG. 28  is a block diagram showing the configuration of a control unit of the control-compliant appliance; 
         FIG. 29  is a block diagram showing the configuration of a tampering detection information generating unit; 
         FIG. 30  is a block diagram showing the configuration of a power storage apparatus; 
         FIG. 31  is a block diagram showing the configuration of a control unit of the power storage apparatus; 
         FIG. 32  is a block diagram showing the configuration of a control unit of the power storage apparatus; 
         FIG. 33  is a block diagram showing the configuration of a tampering detection information generating unit; 
         FIG. 34  is a flowchart useful in explaining a method of registering a power management apparatus; 
         FIG. 35  is a flowchart useful in explaining a specific example of a method of registering a power management apparatus; 
         FIG. 36  is a flowchart useful in explaining a method of registering a control-compliant appliance; 
         FIG. 37  is a flowchart useful in explaining a specific example of a method of registering a control-compliant appliance; 
         FIG. 38  is a flowchart useful in explaining a specific example of a method of registering a control-compliant appliance; 
         FIG. 39  is a flowchart useful in explaining a method of registering a control-compliant outlet; 
         FIG. 40  is a diagram useful in explaining a billing process of a control-compliant appliance that has been temporarily registered; 
         FIG. 41  is a flowchart useful in explaining a billing process of a control-compliant appliance that has been temporarily registered; 
         FIG. 42  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 43  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 44  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 45  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 46  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 47  is a diagram useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 48  is a flowchart useful in explaining a modification to the method of registering a control-compliant appliance; 
         FIG. 49  is a flowchart useful in explaining the operation of a power management apparatus for a managed appliance where an abnormality has occurred; 
         FIG. 50  is a flowchart useful in explaining the operation of a power management apparatus for a managed appliance where an abnormality has occurred; 
         FIG. 51  is a flowchart useful in explaining the operation of a power management apparatus for a managed appliance where an abnormality has occurred; 
         FIG. 52  is a flowchart useful in explaining the operation of a power management apparatus for a managed appliance where an abnormality has occurred; 
         FIG. 53  is a flowchart useful in explaining the operation of a power management apparatus when an abnormality has occurred in the power state; 
         FIG. 54  is a flowchart useful in explaining the operation of a power management apparatus when an abnormality has occurred in the power state; 
         FIG. 55  is a flowchart useful in explaining a method of embedding electronic watermark information; 
         FIG. 56  is a flowchart useful in explaining a method of verifying electronic watermark information; 
         FIG. 57  is a flowchart useful in explaining a method of embedding electronic watermark information; 
         FIG. 58  is a flowchart useful in explaining a method of verifying electronic watermark information; 
         FIG. 59  is a block diagram useful in explaining the configuration of an analysis server; 
         FIG. 60  is a block diagram showing the configuration of an information tampering detecting unit of the analysis server; 
         FIG. 61  is a block diagram showing the configuration of a first verification unit of the analysis server; 
         FIG. 62  is a block diagram showing the configuration of a second verification unit of the analysis server; 
         FIG. 63  is a diagram useful in explaining batteries to be excluded; 
         FIG. 64  is a flowchart useful in explaining a method of protecting against illegal attacks to the power management apparatus; 
         FIG. 65  is a flowchart useful in explaining a method of excluding a battery; 
         FIG. 66A  is a flowchart useful in explaining a method of verifying by an acquired data verification unit of the analysis server; 
         FIG. 66B  is a flowchart useful in explaining a method of verifying by an acquired data verification unit of the analysis server; 
         FIG. 67  is a flowchart useful in explaining a verification process of the first verification unit; 
         FIG. 68  is a flowchart useful in explaining a testing process by a database management unit; 
         FIG. 69  is a diagram useful in explaining updating of a database and generation of a judgment dictionary by the database management unit; 
         FIG. 70  is a flowchart useful in explaining a method of managing a virus definition file by a virus definition file management unit; 
         FIG. 71A  is a flowchart useful in explaining a method implemented by the acquired data verification unit to specify a battery to be excluded; 
         FIG. 71B  is a flowchart useful in explaining a method implemented by the acquired data verification unit to specify a battery to be excluded; 
         FIG. 71C  is a flowchart useful in explaining a method implemented by the acquired data verification unit to specify a battery to be excluded; 
         FIG. 72  is a flowchart useful in explaining a method implemented by the acquired data verification unit to specify a battery to be excluded; 
         FIG. 73  is a diagram useful in explaining the operation flow of multiple power management apparatuses; 
         FIG. 74  is a diagram useful in explaining the operation flow of multiple power management apparatuses; 
         FIG. 75  is a diagram useful in explaining the operation flow of multiple power management apparatuses; 
         FIG. 76  is a block diagram useful in explaining the configuration of a service providing unit of a power management apparatus; 
         FIG. 77  is a block diagram useful in explaining the configuration of a service providing unit of a power management apparatus; 
         FIG. 78  is a diagram useful in explaining linking to a database in a power management apparatus; 
         FIG. 79  is a diagram useful in explaining about security for system-linked entertainment; 
         FIG. 80  is a flowchart useful in explaining the flow of system-linked entertainment; 
         FIG. 81A  is a flowchart useful in explaining the flow of system-linked entertainment; 
         FIG. 81B  is a flowchart useful in explaining the flow of system-linked entertainment; and 
         FIG. 82  is a block diagram useful in explaining the hardware configuration of a power management apparatus according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the appended drawings. Note that, in this specification and the appended drawings, structural elements that have substantially the same function and structure are denoted with the same reference numerals, and repeated explanation of these structural elements is omitted. 
     The following description is given in the order indicated below. 
     (1) First Embodiment 
     (1-1) Overview of Power Management Apparatus 
     (1-2) Configuration of Power Management Apparatus 
     (1-3) Content Displayed by Display Unit 
     (1-4) Concealing Power Consumption Pattern 
     (1-5) Various Control by Power Management Apparatus 
     (1-6) Configuration of Appliance Management Unit 
     (1-7) Configuration of Information Analyzing Unit 
     (1-8) Configuration of Control-Compliant Appliance 
     (1-9) Configuration of Power Storage Apparatus 
     (1-10) Specific Examples of Method of Embedding and Method of Method of Verifying Electronic Watermark Information 
     (1-11) Method of Registering Power Management Apparatus 
     (1-12) Method of Registering Control-Compliant Appliance 
     (1-13) Method of Registering Control-Compliant Outlet 
     (1-14) Billing Process for Temporarily Registered Control-Compliant Appliance 
     (1-15) Modification to Method of Registering Control-Compliant Appliance 
     (1-16) Operation of Power Management Apparatus for Managed Appliance where Abnormality has Occurred 
     (1-17) Operation of Power Management Apparatus when Abnormality Has Occurred in Power State 
     (1-18) Flow of Method of Embedding and Method of Verifying Electronic Watermark Information 
     (1-19) Role of Analysis Server 
     (1-20) Configuration of Analysis Server 
     (1-21) Process Specifying Battery to be Excluded 
     (1-22) Method of Protecting Against Illegal Attacks to Power Management Apparatus 
     (1-23) Method of Excluding Battery 
     (1-24) Verification Process by Acquired Data Verification Unit 
     (1-25) Flow of Verification Process by First Verification Unit 
     (1-26) Testing Process by Database Management Unit 
     (1-27) Updating of Database and Generation of Judgment Dictionary 
     (1-28) Method of Managing Virus Definition File 
     (1-29) Flow of Method of Specifying Battery to be Excluded 
     (1-30) Processing when Multiple Power Management Apparatuses are Present 
     (2) Second Embodiment 
     (2-1) Overview of Second Embodiment 
     (2-2) Configuration of Service Providing Unit 
     (2-3) Linking to Database 
     (2-4) Security for System-Linked Entertainment 
     (2-5) Flow of System-Linked Entertainment 
     (3) Hardware Configuration of Power Management Apparatus According to Embodiment of the Present Invention 
     First Embodiment 
     (1-1) Overview of Power Management Apparatus 
     First, an overview of power management apparatus according to the first embodiment of the present invention will be described. 
       FIG. 1  shows an overall picture of the power management system according to the present embodiment. 
     As shown in  FIG. 1 , the power management system according to the present embodiment includes a local power management system  1 , a wide area network  2 , an external server  3 , a power information gathering apparatus  4 , a power supplier system  5 , a terminal apparatus  6 , and a power trading system  7 . Also, the local power management system  1 , the external server  3 , the power information gathering apparatus  4 , the power supplier system  5 , the terminal apparatus  6 , and the power trading system  7  are connected to the wide area network  2 , and thus can exchange information with each other. 
     Additionally, in this specification, expressions “local” and “wide area” are used. “Local” means a small group configured from elements that can communicate without using the wide area network  2 . On the other hand, “wide area” means a large group including elements that communicate via the wide area network  2 . Also, a small group configured from elements arranged inside the local power management system  1  may be specifically expressed by the expression “local.” On the other hand, the entire power management system shown in  FIG. 1  may be expressed by the expression “wide area.” 
     Now, the power management system described above attempts, as with the smart grid initiative described above, to enhance efficiency of power usage, and to appropriately manage various appliances operating on power, power storage means that stores power, power generating means that generates power, power supply means that supplies power from a power supply, and the like. The targets of power management in this power management system are the appliances, the power storage means, the power generating means, the power supply means, and the like provided in the local power management system  1 . Additionally, a system in the smart grid initiative called HEMS (Home Energy Management System) or BEMS (Building Energy Management System) is an example of the local power management system  1 . 
     As shown in  FIG. 1 , the local power management system  1  includes the power management apparatus  11 , and a managed block  12 . The power management apparatus  11  undertakes a role of managing the appliances, the power storage means, the power generating means, the power supply means, and the like provided in the local power management system  1 . For example, the power management apparatus  11  permits or prohibits power supply to each appliance. Also, the power management apparatus  11  carries out authentication on each appliance to identify the appliance or to confirm validity of the appliance. Then, the power management apparatus  11  gathers information on power consumption or the like from each appliance. 
     Furthermore, the power management apparatus  11  acquires information on the amount of stored power or the like from the power storage means. Then, the power management apparatus  11  carries out charge/discharge control on the power storage means. Furthermore, the power management apparatus  11  acquires information on the amount of power generation or the like from the power generating means. Also, the power management apparatus  11  acquires information on the amount of power supplied from outside from the power supply means. In this manner, the power management apparatus  11  acquires information from the appliances, the power storage means, the power generating means, and the power supply means provided in the local power management system  1 , and controls input/output of power. Of course, the power management apparatus  11  carries out, as appropriate, similar management of structural elements other than the appliances, the power storage means, the power generating means, and the power supply means. Furthermore, the power management apparatus  11  can also carry out management of not only power but also ecology in general, such as CO 2 , water resources and the like, the reduction in which can be quantified. That is, the power management apparatus  11  can function also as an eco-management apparatus. Incidentally, in the following, an explanation will be made by taking power as an example of resources whose reduction can be quantified. 
     In the local power management system  1  shown in  FIG. 1 , the structural elements such as the appliances, the power storage means, the power generating means, and the power supply means, which are the targets of power management, are included in the managed block  12 . The structural elements included in the managed block  12  and the power management apparatus  11  are capable of directly or indirectly exchanging information. Also, the power management apparatus  11  may be configured to be able to exchange information with the power information gathering apparatus  4 . The power information gathering apparatus  4  manages information on power supplied from the power supplier system  5  managed by a power supplier. Additionally, an appliance called a smart meter in the smart grid initiative is an example of the power information gathering apparatus  4 . 
     The power supplier system  5  supplies power to each local power management system  1 . Then, the power supplied from the power supplier system  5  is supplied to the managed block  12  in the local power management system  1  via the power information gathering apparatus  4 . At this point, the power information gathering apparatus  4  acquires information, for example, on the amount of power supplied to the managed block  12 . Then, the power information gathering apparatus  4  transmits the acquired information on the amount of power or the like to the power supplier system  5 . By using such a mechanism, the power supplier system  5  gathers information relating to power consumption or the like of the managed block  12  in each local power management system  1 . 
     Furthermore, the power supplier system  5  refers to the gathered information relating to power consumption or the like, controls the power information gathering apparatus  4 , and controls the amount of power supply such that efficient power usage by the managed block  12  or the entire power management system is realized. At this point, the power information gathering apparatus  4  restricts the amount of power supplied from the power supplier system  5  to the managed block  12 , or lifts the restriction on the amount of power according to the power consumption of the managed block  12 . Additionally, the power supplier may be a power company, a corporate or non-corporate power generation manager owning a power station, a corporate or non-corporate power storage manager owning a power storage facility, or the like, for example. 
     However, under current situations, a power company is likely to be the power supplier and, in this specification, an explanation will be made assuming a case where the power company is the power supplier. Also, most of the externally-supplied power is at present purchased from the power company, which is the power supplier. However, in the future, the electricity market may become active and the power purchased in the electricity market may cover most of the externally-supplied power. In such a case, it is assumed that the local power management system  1  will be supplied with power from the power trading system  7 , as shown in  FIG. 1 . 
     The power trading system  7  carries out processes relating to power trading such as placement of a sell or buy order in the electricity market, price calculation after the execution of an order, a settlement process, placement of order for power supply, and the like. Furthermore, in the example of  FIG. 1 , reception of power for which an order has been executed in the electricity market is also carried out by the power trading system  7 . Thus, in the example of  FIG. 1 , according to the type of an executed order, the power is supplied from the power trading system  7  to the local power management system  1 , or from the local power management system  1  to the power trading system  7 . Furthermore, placement of an order to the power trading system  7  is performed automatically or manually by using the power management apparatus  11 . 
     Furthermore, the power management system shown in  FIG. 1  includes a plurality of local power management systems  1 . As described above, each local power management system  1  includes the power management apparatus  11 . The plurality of power management apparatuses  11  can mutually exchange information via the wide area network  2  or a secure communication path (not shown). There may also be provided a mechanism for supplying power from one local power management system  1  to another local power management system  1 . In such a case, the power management apparatuses  11  of both systems carry out information exchange relating to reception of power, and perform control to transmit the amount of power appropriately decided by the information exchange. 
     For its part, the power management apparatus  11  may be configured to be operable by an external terminal device  6  connected via the wide area network  2 . For example, a user may want to check the power state of the local power management system  1  that the user manages, by using the terminal apparatus  6 . In such a case, if the power management apparatus  11  is configured to be operable by the terminal apparatus  6 , the user is enabled to have the power state of the local power management system  1  that the user manages displayed by the terminal apparatus  6  and to check the power state. The user is also enabled to perform power trading by the power management apparatus  11  by using the terminal apparatus  6 . 
     Additionally, the terminal apparatus  6  may be provided inside the local power management system  1 . In this case, the terminal apparatus  6  connects to the power management apparatus  11  by using a communication path provided in the local power management system  1  without using the wide area network  2 . One advantage of using the terminal apparatus  6  is that the user does not have to go to the installation location of the power management apparatus  11 . That is, if the terminal apparatus  6  can be used, the power management apparatus  11  can be operated from an arbitrary place. Additionally, as a concrete form of the terminal apparatus  6 , there can be assumed, for example, a mobile phone, a mobile information terminal, a notebook computer, a portable game machine, an information appliance, a facsimile, a fixed-line phone, an audio/video appliance, a car navigation system, or an electric vehicle. 
     In the foregoing, power management in the power management system shown in  FIG. 1  has been briefly described while referring to the operation or function of each structural element. However, the above-described power management apparatus  11  has, in addition to the function relating to power management, a function of providing various services to a user by using various pieces of information gathered from the managed block  12  and the like. 
     Information that can be gathered by the power management apparatus  11  may be, for example, a model number or an appliance ID of each appliance (hereinafter, appliance information), information relating to the profile of a user (hereinafter, user information), information relating to a billing account or a credit card of a user (hereinafter, billing information), registration information relating to a service to be used (hereinafter, service information), or the like. The appliance information mentioned above is set in each appliance in advance or is manually input by a user. Also, the user information, the billing information, and the service information mentioned above are, in many cases, manually input to the power management apparatus  11  by a user. Additionally, input method of the information is not limited to these examples, and may be changed to arbitrary input method. Also, in the following explanation, the appliance information, the user information, the billing information, and the service information will be referred to as “initial information.” 
     The information that can be gathered by the power management apparatus  11  may be, in addition to the initial information, information relating to specifications of a battery connected to each appliance (hereinafter, appliance battery information), information relating to the state of each appliance or the like (including the power storage means, the power generating means, the power supply means, and the like) (hereinafter, appliance state information), information that can be acquired from an external system or server connected to the wide area network  2  (hereinafter, external information), and the like. The appliance state information mentioned above may be, for example, the discharge voltage or the amount of stored power of the power storage means at the time point of information gathering, the power generation voltage or the amount of power generation of the power generating means, power consumption of each appliance, and the like. Furthermore, the external information mentioned above may be the unit market price of power acquired from the power trading system  7 , a list of available services acquired from the external server  3 , and the like. Additionally, in the following explanation, the appliance battery information, the appliance state information, and the external information will be referred to as “primary information.” 
     Furthermore, the power management apparatus  11  can calculate, by itself or by using the function of the external server  3 , secondary information by using the initial information and the primary information. For example, the power management apparatus  11  analyzes the primary information described above, and calculates an index value indicating the balance between the power supplied from the power supplier system  5 , the power generated by the power generating means, the power charged/discharged by the power storage means, and the power consumed by the managed block  12  (hereinafter, a balance index). Also, the power management apparatus  11  calculates a billing status and a CO 2  reduction status based on power consumption. Furthermore, the power management apparatus  11  calculates the degree of consumption of each appliance (a proportion of duration of use to duration of life, or the like) based on the initial information, or analyzes a user&#39;s life pattern based on the change over time in the consumed power. 
     Also, the power management apparatus  11  obtains various pieces of information (hereinafter, tertiary information) by performing calculation using the secondary information or by performing information exchange with a system or a server connected to the wide area network  2  or another power management apparatus  11 . For example, the power management apparatus  11  obtains information relating to the status of sell/buy order or price in the electricity market (hereinafter, market data), information on the amount of surplus power or of deficit power in a neighbouring region (hereinafter, regional power information), information on an appliance suitable for a user&#39;s life pattern from the standpoint of promoting efficient power usage (hereinafter, appliance recommendation information), security information relating to a computer virus or the like, or appliance risk information relating to a fault in an appliance or the like. 
     By appropriately using the initial information, the primary information, the secondary information, and the tertiary information described above, the power management apparatus  11  can provide various services to a user. Meanwhile, the power management apparatus  11  is to hold important information relating to a user&#39;s privacy or the security of the local power management system  1 . Also, the power management apparatus  11  is in a place to permit or prohibit power supply to the managed block  12 . Thus, a high level of security is wanted from the power management apparatus  11  so that an attack from the outside of the local power management system  1  or an illegal behaviour performed within the local power management system  1  can be prevented. 
     As an attack that the power management apparatus  11  receives from the outside of the local power management system  1 , there can be conceived a DoS attack (Denial of Service attack), a computer virus, or the like. A firewall is of course provided between the local power management system  1  and the wide area network  2 , but a stricter security measure is wanted for the reason stated above. Furthermore, as the illegal behaviour performed within the local power management system  1 , there can be conceived illegal modification of an appliance, the power storage means, or the like, falsification of information, connection of an unauthorized appliance, or the like. Furthermore, a measure against use, by a malicious third party, of information on consumed power reflecting a user&#39;s life pattern, or detection/recovery of breakdown (ignition or the like in some cases) of each appliance or the power management apparatus  11  may become necessary from the viewpoint of enhancing the security level. 
     As will be described later, the power management apparatus  11  has a function of realizing such high security level as described above. The power management apparatus  11  realizes power management for the managed block  12 , service provision based on the initial information, the primary information, the secondary information, and the tertiary information gathered from the managed block  12 , and the like, while maintaining the security level. Additionally, the maintenance of the high security level by the power management apparatus  11  may not be realized by the power management apparatus  11  alone. Accordingly, an appliance, the power storage means, the power generating means, the power supply means, and the like, provided in the managed block  12  are to attempt to maintain the security level in cooperation with the power management apparatus  11 . Additionally, such structural elements of the managed block  12  will also be described later in detail. 
     Configuration of Managed Block 
     A configuration of the managed block  12  will be described in detail here with reference to  FIGS. 2 to 4 .  FIG. 2  shows the configuration of the managed block  12 . Also,  FIG. 3  shows a configuration of a communication network within the managed block  12 . Furthermore,  FIG. 4  shows specific configurations of main structural elements for exchanging information with the power management apparatus  11 . 
     First, reference will be made to  FIG. 2 . As shown in  FIG. 2 , the managed block  12  includes a power distribution apparatus  121 , an AC/DC converter  122 , a control-compliant outlet  123 , an electric vehicle  124 , a control-compliant appliance  125 , a non-control-compliant appliance  126 , an outlet expansion apparatus  127 , a power storage apparatus  128 , a first power generating apparatus  129 , a second power generating apparatus  130 , and an environmental sensor  131 . 
     Additionally, the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , and the outlet expansion apparatus  127  are examples of the appliance described above. Also, the power storage apparatus  128  is an example of the power storage means described above. Furthermore, the first power generating apparatus  129  and the second power generating apparatus  130  are examples of the power generating means described above. The control-compliant outlet  123  and the outlet expansion apparatus  127  are also examples of the power supply means described above. Furthermore, the non-control-compliant appliance  126  is not directly subject to power management by the power management apparatus  11 , and thus is not, by itself, an example of the appliance described above. However, as will be described later, by being combined with the outlet expansion apparatus  127 , the non-control-compliant appliance  126  will be able to be managed by the power management apparatus  11 , and will be an example of the appliance described above. 
     Flow of Power 
     Power supplied from the power supplier system  5 , the power trading system  7 , or another local power management system  1  (hereinafter, external power) is input to the power distribution apparatus  121 . External AC power is assumed to be input to the power distribution apparatus  121  in the example of  FIG. 2 , but external DC power may also be input. However, for the sake of explanation, it is assumed in the following that external AC power is input to the power distribution apparatus  121 . The external power input to the power distribution apparatus  121  is converted from AC to DC by the AC/DC converter  122 , and is input to the control-compliant outlet  123  or the power storage apparatus  128 . 
     Furthermore, power discharged from the power storage apparatus  128  (hereinafter, discharged power) is also input to the power distribution apparatus  121 . The discharged power output from the power storage apparatus  128  is converted from DC to AC by the AC/DC converter  122 , and is input to the power distribution apparatus  121 . The discharged AC power input to the power distribution apparatus  121  is converted from AC to DC by the AC/DC converter  122 , and is input to the control-compliant outlet  123 . However, to avoid a loss in the discharged power at the AC/DC converter  122 , the discharged power may also be supplied from the power storage apparatus  128  to the control-compliant outlet  123  without going through the AC/DC converter  122 . 
     In addition to the external power input via the power distribution apparatus  121 , power generated by the first power generating apparatus  129  and the second power generating apparatus  130  (hereinafter, generated power) is input to the power storage apparatus  128 . Additionally, in the example of  FIG. 2 , the generated power generated by the first power generating apparatus  129  and the second power generating apparatus  130  is temporarily stored in the power storage apparatus  128 . However, the generated power generated by the first power generating apparatus  129  and the second power generating apparatus  130  may also be input to the AC/DC converter  122  or the control-compliant outlet  123  without going through the power storage apparatus  128 . However, in many cases, supply of the generated power output from the first power generating apparatus  129  is unstable due to the climate or the environment. Thus, in the case of using the generated power output from the first power generating apparatus  129 , the generated power is preferably used after being temporarily stored in the power storage apparatus  128 . 
     Additionally, the first power generating apparatus  129  is power generating means for generating power using renewable energy. For example, the first power generating apparatus  129  is a photovoltaic apparatus, a wind power generating apparatus, a geothermal power generating apparatus, a hydraulic power generating apparatus, or the like. On the other hand, the second power generating apparatus  130  is power generating means for generating power using non-renewable energy which is environment-friendly compared to, for example, thermal power generation that generates power by combusting gasoline, coal, or the like, and using the combustion. For example, the second power generating apparatus  130  is a fuel cell, a natural gas power generating apparatus, a biomass power generating apparatus, or the like. Incidentally, in the case hydrogen, which is the fuel for power generation by the fuel cell, is generated using power derived from renewable energy, the fuel cell is power generating means that generates power without using non-renewable energy. 
     The generated power generated by the first power generating apparatus  129  and the second power generating apparatus  130 , and the power stored in the power storage apparatus  128  are, on the one hand, input to the control-compliant outlet  123  via the power distribution apparatus  121  or the AC/DC converter  122 , and, on the other hand, may be purchased by the power supplier system  5 , the power trading system  7 , or the like. In such a case, the generated power generated by the first power generating apparatus  129  and the second power generating apparatus  130 , and the discharged power output from the power storage apparatus  128  are converted by the AC/DC converter  122  from DC to AC, and are transmitted to the power supplier system  5 , the power trading system  7 , or the like, via the power distribution apparatus  121   
     In the foregoing, the flow of power in the managed block  12  has been roughly described. Particularly, a distribution path of the power flowing via the power distribution apparatus  121  has been described here. As described above, the power distribution apparatus  121  undertakes a role of dividing the distribution path of power within the managed block  12 . Thus, if the power distribution apparatus  121  stops, the distribution of power within the managed block  12  is disrupted. Therefore, the power distribution apparatus  121  is provided with an uninterruptible power supply (UPS). Additionally, in the example of  FIG. 2 , the power distribution apparatus  121  is provided separately from the power management apparatus  11 , but the power distribution apparatus  121  and the power management apparatus  11  may be installed in the same casing. 
     Authentication at the Time of Power Supply 
     In the managed block  12 , the power flowing to the control-compliant outlet  123  or the power storage apparatus  128  via the power distribution apparatus  121  is managed by the power management apparatus  11 . For example, the power management apparatus  11  controls the power distribution apparatus  121  and supplies power to the control-compliant outlet  123  or stops the supply of power to the control-compliant outlet  123 . 
     The power management apparatus  11  also carries out authentication of the control-compliant outlet  123 . Then, the power management apparatus  11  supplies power to the control-compliant outlet  123  for which authentication has been successful, and stops supply of power to the control-compliant outlet  123  for which authentication has failed. In this manner, supply or non-supply of power in the managed block  12  is determined by the success or failure of authentication by the power management apparatus  11 . Authentication by the power management apparatus  11  is carried out not only on the control-compliant outlet  123 , but also on the electric vehicle  124 , the control-compliant appliance  125 , and the outlet expansion apparatus  127 . Incidentally, authentication by the power management apparatus  11  is not carried out on the non-control-compliant appliance  126 , which does not possess a communication function with the power management apparatus  11  nor a computational function necessary for authentication 
     Accordingly, the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127  which has been authenticated can be supplied with power based on control by the power management apparatus  11 . However, the non-control-compliant appliance  126 , which is not, by itself, to be authenticated, will not be supplied with power based on control by the power management apparatus  11 . Accordingly, power is continuously supplied to the non-control-compliant appliance  126  independently of control by the power management apparatus  11 , or power is not at all supplied thereto. However, by having the outlet expansion apparatus  127  carry out authentication instead, it becomes possible for the non-control-compliant appliance  126  to be supplied with power based on control by the power management apparatus  11 . 
     Summary of Appliance Function 
     The functions of the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the non-control-compliant appliance  126 , and the outlet expansion apparatus  127  will be briefly summarized here. 
     Control-Compliant Outlet  123   
     First, the function of the control-compliant outlet  123  will be summarized. The control-compliant outlet  123  has terminals to be connected with power plugs of the electric vehicle  124 , the control-compliant appliance  125 , the non-control-compliant appliance  126 , and the outlet expansion apparatus  127 . Furthermore, the control-compliant outlet  123  has a function of supplying power supplied via the power distribution apparatus  121  to the electric vehicle  124 , the control-compliant appliance  125 , the non-control-compliant appliance  126 , and the outlet expansion apparatus  127  connected to the terminals. That is, the control-compliant outlet  123  has a function as a power supply outlet. 
     The control-compliant outlet  123  also has various functions necessary for being authenticated by the power management apparatus  11 . For example, the control-compliant outlet  123  has a communication function for exchanging information with the power management apparatus  11 . This communication function is realized by cable communication by a power line or a signal line, or by providing the control-compliant outlet  123  with a communication module for wireless communication. The control-compliant outlet  123  also has a computational function for performing computation necessary at the time of authentication. Furthermore, the control-compliant outlet  123  holds identification information such as an appliance ID and key information necessary for authentication. By using these functions and information, the control-compliant outlet  123  is enabled to be authenticated by the power management apparatus  11 . Additionally, the type of authentication may be mutual authentication using a random number, or public key authentication using a pair of a secret key and a public key. 
     Furthermore, the control-compliant outlet  123  may also have state display means for displaying success/failure of authentication with the power management apparatus  11  and a state during authentication (hereinafter, authentication state). In this case, the state display means provided in the control-compliant outlet  123  may display the authentication states of the electric vehicle  124 , the control-compliant appliance  125 , and the outlet expansion apparatus  127  connected to the control-compliant outlet  123 . Furthermore, this state display means may also display whether an appliance connected to the control-compliant outlet  123  is the non-control-compliant appliance  126  or not. Additionally, this state display means is configured from an indicator lamp such as a LED or a small bulb, or a display device such as an LCD or an ELD 
     As has been described, power is supplied via the power distribution apparatus  121  by control by the power management apparatus  11  to the control-compliant outlet  123  for which authentication by the power management apparatus  11  has been successful. On the other hand, supply of power to the control-compliant outlet  123  for which authentication has failed is stopped by control by the power management apparatus  11 . As such, with power supply being controlled according to the success/failure of authentication, an unauthorized power supply outlet can be prevented from connecting to the power distribution apparatus  121 . It becomes possible also to easily detect a power supply outlet fraudulently connected to the power distribution apparatus  121 . Furthermore, in the case the state display means is provided in the control-compliant outlet  123 , the authentication state of the control-compliant outlet  123  can be easily grasped, and authentication failure and breakdown of the control-compliant outlet  123  can be easily distinguished. 
     Now, the form of the control-compliant outlet  123  is not limited to the form of a power point for connecting a power plug. For example, a control-compliant outlet  123  that has a built-in coil that supplies power by using electromagnetic induction as with a reader/writer for a non-contact IC card, and that has a surface form without the form of a power point can also be realized. In such a case, as with a non-contact IC card, a coil for generating an induced electromotive force from a magnetic field generated by the control-compliant outlet  123  is provided in the electric vehicle  124 , the control-compliant appliance  125 , and the outlet expansion apparatus  127 . According to such a configuration, supplying or receiving of power without the use of a power plug is made possible. Additionally, in the case of using electromagnetic induction, exchange of information using modulation of magnetic field is made possible between the control-compliant outlet  123  and the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127 . 
     Furthermore, the control-compliant outlet  123  has a function of measuring the amount of power supplied to the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127  connected to the terminal. Furthermore, the control-compliant outlet  123  has a function of notifying the measured amount of power to the power management apparatus  11 . Also, the control-compliant outlet  123  may have a function of acquiring the primary information from the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127  that is connected to the terminal and of transmitting the acquired primary information to the power management apparatus  11 . As such, with the information which has been measured or acquired by the control-compliant outlet  123  transmitted to the power management apparatus  11 , it becomes possible for the power management apparatus  11  to grasp power status or to perform power supply control for each individual control-compliant outlet  123 . 
     Electric Vehicle  124   
     Next, the function of the electric vehicle  124  will be summarized. The electric vehicle  124  includes a battery for storing power. The electric vehicle  124  also includes a driving mechanism that is driven using power discharged from the battery. In the case the electric vehicle  124  is an electric vehicle or a plug-in hybrid electric vehicle, this driving mechanism will include a motor, a gear, a shaft, wheels, tires, and the like, for example. The driving mechanisms of other electric vehicles  124  will at least include a motor. Furthermore, the electric vehicle  124  includes a power plug used at the time of charging the battery. Power can be received by connecting this power plug to the control-compliant outlet  123 . Incidentally, in the case of a method where the control-compliant outlet  123  supplies power by using the electromagnetic induction, a coil that generates an induced electromotive force when placed in a magnetic field is provided in the electric vehicle  124 . 
     The electric vehicle  124  also has various functions necessary for being authenticated by the power management apparatus  11 . For example, the electric vehicle  124  has a communication function for exchanging information with the power management apparatus  11 . This communication function is realized by cable communication by a power line or a signal line, or by providing the electric vehicle  124  with a communication module for wireless communication. The electric vehicle  124  also has a computational function for performing computation necessary at the time of authentication. Furthermore, the electric vehicle  124  holds identification information such as an appliance ID and key information necessary for authentication. By using these functions and information, the electric vehicle  124  is enabled to be authenticated by the power management apparatus  11 . Additionally, the type of authentication may be mutual authentication using a random number, or public key authentication using a pair of a secret key and a public key. 
     Furthermore, the electric vehicle  124  also has a function of transmitting, to the power management apparatus  11 , appliance battery information relating to a battery that is mounted, such as a remaining battery level, a charge amount, and a discharge amount. User information relating to a user owning the electric vehicle  124 , and appliance information relating to fuel efficiency, performance, or the like, of the electric vehicle  124  are also transmitted to the power management apparatus  11 . With these pieces of information transmitted to the power management apparatus  11  from the electric vehicle  124 , it becomes possible for the power management apparatus  11  to carry out processes such as billing using the user information, and taxation based on the user information and the appliance information. For example, a process of imposing an environmental tax calculated based on the amount of CO 2  emissions, a process of displaying a mileage based on the remaining battery level, and the like, will be able to be carried out by the power management apparatus  11 . 
     Additionally, it is also conceivable to use the battery of the electric vehicle  124  instead of the power storage apparatus  128 . For example, the battery of the electric vehicle  124  may be used instead of the power storage apparatus  128  when it is temporarily not possible to use the power storage apparatus  128 , such as when the power storage apparatus  128  is broken down or is being exchanged. Furthermore, since the electric vehicle  124  is itself movable, it can carry external power as a material. That is, it can be used as a movable power storage apparatus  128 . Due to such advantage, it may also be useful to have the electric vehicle  124  act as back-up power supply in case of disaster or emergency. Such usage can, of course, be realized within the framework of the local power management system  1  according to the present embodiment. 
     Control-Compliant Appliance  125   
     Next, the function of the control-compliant appliance  125  will be summarized. The control-compliant appliance  125  has various functions necessary for being authenticated by the power management apparatus  11 . For example, the control-compliant appliance  125  has a communication function for exchanging information with the power management apparatus  11 . This communication function is realized by cable communication by a power line or a signal line, or by providing the control-compliant appliance  125  with a communication module for wireless communication. The control-compliant appliance  125  also has a computational function for performing computation necessary at the time of authentication. Furthermore, the control-compliant appliance  125  holds identification information such as an appliance ID and key information necessary for authentication. By using these functions and information, the control-compliant appliance  125  is enabled to be authenticated by the power management apparatus  11 . Additionally, the type of authentication may be mutual authentication using a random number, or public key authentication using a pair of a secret key and a public key. 
     Furthermore, the control-compliant appliance  125  also has a function of transmitting, to the power management apparatus  11 , appliance battery information relating to a battery that is mounted, such as a remaining battery level, a charge amount, and a discharge amount. User information relating to a user owning the control-compliant appliance  125 , and appliance information relating to the type, performance, or the like, of the control-compliant appliance  125  are also transmitted to the power management apparatus  11 . With these pieces of information transmitted to the power management apparatus  11  from the control-compliant appliance  125 , it becomes possible for the power management apparatus  11  to carry out processes such as billing using the user information, and taxation based on the user information and the appliance information. For example, a process of imposing an environmental tax calculated based on the amount of CO 2  emissions, a display process for recommending an appliance with higher environmental performance, and the like, will be able to be carried out by the power management apparatus  11 . 
     Non-Control-Compliant Appliance  126 , Outlet Expansion Apparatus  127   
     Next, the functions of the non-control-compliant appliance  126  and the outlet expansion apparatus  127  will be summarized. Unlike the control-compliant outlet  123 , the electric vehicle  124 , and the control-compliant appliance  125  described above, the non-control-compliant appliance  126  does not possess a function necessary to be authenticated by the power management apparatus  11 . That is, the non-control-compliant appliance  126  is an existing home electric appliance, an existing video appliance, or the like. The non-control-compliant appliance  126 , which does not pass authentication, is not enabled to be subjected to power management by the power management apparatus  11 , and in some cases, is not enabled to receive power. Therefore, to enable use of the non-control-compliant appliance  126  in the local power management system  1 , delegate means for performing authentication becomes necessary. 
     The outlet expansion apparatus  127  undertakes two roles. One role is a function of performing delegate authentication such that the non-control-compliant appliance  126  is enabled to be used in the local power management system  1 . The other role is a function of increasing the number of appliances to be connected to the control-compliant outlet  123 . One or more terminals to be connected with the power plug of the electric terminal  124 , the control-compliant appliance  125 , or the non-control-compliant appliance  126  is provided to the outlet expansion apparatus  127 . When using the outlet expansion apparatus  127  provided with a plurality of terminals, the number of the electric vehicles  124 , the control-compliant appliances  125 , and the non-control-compliant appliances  126  that can be connected to the control-compliant outlet  123  can be increased. That is, the outlet expansion apparatus  127  functions as a power strip having an advanced function. 
     In the foregoing, the functions of the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the non-control-compliant appliance  126 , and the outlet expansion apparatus  127  have been briefly summarized. Incidentally, the functions described above are not the only functions of the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the non-control-compliant appliance  126 , and the outlet expansion apparatus  127 . Taking these functions as basics, functions necessary for operation of power management by the power management apparatus  11  described below will be further supplemented. 
     Communication Function 
     Here, a communication function of the power management apparatus  11 , the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the outlet expansion apparatus  127 , or the like, within the local power management system  1  will be described with reference to  FIG. 3 . As shown in  FIG. 3 , in the local power management system  1 , short-range wireless communication, wireless LAN, power line communication, or the like, is used, for example. For example, ZigBee is an example of the short-range wireless communication. Also, PLC is an example of the power line communication. 
     As shown in  FIG. 2 , in the local power management system  1 , the control-compliant outlet  123  and appliances connected to the control-compliant outlet  123  are connected to the power distribution apparatus  121  by power lines. Thus, a communication network based on the power line communication can be easily constructed by using these power lines. On the other hand, in the case of using the short-range wireless communication, a communication network can be constructed by connecting each appliance in an ad-hoc manner, as shown in  FIG. 3 . Also, in the case of using the wireless LAN, each appliance can be directly connected to the power management apparatus  11 . Accordingly, a necessary communication network can be constructed within the local power management system  1  by using any of the communication methods. 
     However, as shown in  FIG. 3 , the non-control-compliant appliance  126  is sometimes not enabled to be connected to the power management apparatus  11  by using the communication network. Thus, in the case of using the non-control-compliant appliance  126 , the non-control-compliant appliance  126  has to be connected to the outlet expansion apparatus  127 . Additionally, even in the case of using a non-control compliant outlet not having the communication function nor an authentication function, connection to the power management apparatus  11  via the communication network is enabled by using the function of the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127 , if the electric vehicle  124 , the control-compliant appliance  125 , or the outlet expansion apparatus  127  is connected to the non-control compliant outlet. Of course, in the case the non-control-compliant appliance  126  is connected to the non-control compliant outlet, connection to the communication network is not enabled, and thus control by the power management apparatus  11  is not enabled. 
     Incidentally, the power information gathering apparatus  4  may be included, as a connection destination, in the communication network constructed within the local power management system  1 , as shown in  FIG. 3 . Also, information may be exchanged between the electric vehicle  124  or the control-compliant appliance  125  and the power information gathering apparatus  4  by using this communication network. Of course, the power management apparatus  11  and the power information gathering apparatus  4  may exchange information by using this communication network. As such, the structure of the communication network constructed within the local power management system  1  should be appropriately set according to the mode of embodiment. Additionally, this communication network is to be constructed by a sufficiently secure communication channel. Also, a mechanism that allows to guarantee security of information flowing through the communication channel should be provided. 
     Specific Examples of Appliances and Various Apparatuses 
     Here, specific examples of some structural elements of the local power management system  1  will be introduced with reference to  FIG. 4 . As shown in  FIG. 4 , structural elements that possibly exchange information with the power management apparatus  11  include, for example, the electric vehicle  124 , the control-compliant appliance  125  (a smart appliance), the non-control-compliant appliance  126  (a legacy appliance), the power storage apparatus  128 , the first power generating apparatus  129 , the second power generating apparatus  130 , and the like. 
     As the electric vehicle  124 , an electric vehicle and a plug-in hybrid electric vehicle can be given as specific examples, for example. Also, as the control-compliant appliance  125  and the non-control-compliant appliance  126 , a home appliance, a personal computer, a mobile phone, and a video appliance can be given as specific examples, for example. As the power storage apparatus  128 , a lithium-ion rechargeable cell, a NAS rechargeable cell, and a capacitor can be given as specific examples, for example. Also, as the first power generating apparatus  129 , a photovoltaic apparatus, a wind power generating apparatus, and a geothermal power generating apparatus can be given as specific examples, for example. Furthermore, as the second power generating apparatus  130 , a fuel cell, a natural gas power generating apparatus, and a biomass power generating apparatus can be given as specific examples, for example. As described, various apparatuses and appliances are used as the structural elements of the local power management system  1 . 
     In the foregoing, the configuration of the managed block  12  has been described. However, the function of each structural element included in the managed block  12  is not limited to that described above. The function of each structural element is supplemented as necessary for power management by the power management apparatus  11 . Additionally, a supplementary function of each structural element will be described in detail in the explanation of the configuration of the power management apparatus  11  and other structural elements to be described later. 
     Configuration of External Server 
     Next, the configuration of the external server  3  will be described with reference to  FIG. 5 . As shown in  FIG. 5 , as the external server  3 , a service providing server  31 , a billing server  32 , a system management server  33 , an analysis server  34 , a certificate authority server  35 , a manufacturer server  36 , and a map DB server  37  are used, for example. 
     The service providing server  31  has a function of providing a service that uses a function of the power management apparatus  11  or the like. The billing server  32  has a function of providing the power management apparatus  11  with billing information according to the power consumed in the local power management system  1 , and requesting a user to settle the usage fee, based on information on the amount of power managed by the power management apparatus  11 . Also, the billing server  32  carries out, in cooperation with the service providing server  31 , a billing process on a service used by a user. Additionally, the billing process may be carried out for an owner user of the electric vehicle  124 , the control-compliant appliance  125 , or the like, that consumed power, or may be carried out for a user of the power management apparatus  11  managing information on the power consumed. 
     The system management server  33  has a function of managing the entire power management system shown in  FIG. 1  or of managing the power management system on a regional basis. For example, as shown in  FIG. 6 , the system management server  33  grasps a usage status in the local power management system  1  of a user # 1 , a usage status in the local power management system  1  of a user # 2 , and a usage status in the local power management system  1  of a user # 3 , and provides the billing server  32  or the like with necessary information. 
     In the example of  FIG. 6 , a case is assumed where the user # 1  used power in the local power management systems  1  of the user # 1  himself/herself, the user # 2 , and the user # 3 . In this case, an appliance ID of the user # 1  that consumed power and usage information (power consumption or the like) are gathered by the system management server  33 , and user information of the user # 1  and the usage information are transmitted from the system management server  33  to the billing server  32 . Furthermore, the system management server  33  calculates billing information (billed amount, or the like) based on the gathered usage information, and provides the same to the user # 1 . For its part, the billing server  32  charges the user # 1  for a sum corresponding to the billing information. 
     As described, with the system management server  33  exercising general control over a plurality of local power management systems  1 , a mechanism is realized of billing a user who has used power even if the user has used power in the local power management system  1  of another user. Especially, charging of the electric vehicle  124  is, in many cases, performed outside the local power management system  1  managed by oneself. In such a case, if the function described above of the system management server  33  is used, fee can be reliably billed to the user of the electric vehicle  124 . 
     The analysis server  34  has a function of analyzing information gathered by the power management apparatus  11 , or information that another server connected to the wide area network  2  holds. For example, in the case of optimizing region-based power supply control, the amount of information gathered from the local power management systems  1  will be huge, and to calculate an optimal control method for each local power management system  1  by analyzing the information, tremendous amount of computation will have to be performed. Such computation is burdensome to the power management apparatus  11 , and thus is carried out by using the analysis server  34 . Additionally, the analysis server  34  can also be used for other various computational processes. Furthermore, the certificate authority server  35  is for authenticating a public key, and for issuing a public key certificate. 
     The manufacturer server  36  is managed by the manufacturer of an appliance. For example, the manufacturer server  36  of the electric vehicle  124  holds information relating to the design of the electric vehicle  124 . Similarly, the manufacturer server  36  of the control-compliant appliance  125  holds information relating to the design of the control-compliant appliance  125 . Furthermore, the manufacturer server  36  holds information for identifying each manufactured appliance, such as each electric vehicle  124  and each control-compliant appliance  125 . The manufacturer server  36  has a function of identifying the electric vehicle  124  or the control-compliant appliance  125  located within each local power management system  1  by using these pieces of information and cooperating with the power management apparatus  11 . By using this function, the power management apparatus  11  can carry out authentication of the electric vehicle  124  or the control-compliant appliance  125 , or detect connection of an unauthorized appliance. 
     The map DB server  37  holds a map database. Accordingly, a server or the power management apparatus  11  connected to the wide area network  2  can access the map DB server  37  and use the map database. For example, in a case a user used power outside his/her local power management system  1 , the system management server  33  can search the usage location from the map database and provide the user with information on the usage location together with billing information. As described, there are various types of external server  3 , and in addition to the server configuration illustrated here, different types of external servers  3  can also be added as appropriate. 
     Configuration of Power Management Apparatus 
     In the foregoing, an overall picture of the power management system according to the present embodiment has been described. In the following, the configuration of the power management apparatus  11  mainly in charge of power management in the power management system will be described with reference to  FIGS. 7 to 9 . 
     Overview of Function 
     First, an overall functional configuration of the power management apparatus  11  will be described with reference to  FIG. 7 . As shown in  FIG. 7 , the power management apparatus  11  includes a local communication unit  111 , an information management unit  112 , a storage unit  113 , a wide area communication unit  114 , a control unit  115 , a display unit  116 , an input unit  117 , and a service providing unit  118 . 
     The local communication unit  111  is communication means for communicating via a communication network constructed within the local power management system  1 . The information management unit  112  is means for managing appliance information of each structural element included in the local power management system  1  and information relating to power. Also, the authentication process for the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the outlet expansion apparatus  127 , or the like, is carried out by the information management unit  112 . The storage unit  113  is storage means for holding information used for authentication and information used for power management. The storage unit  113  stores key information relating to a key pair composed of a secret key and a public key held by the power management apparatus  11 , a common key, or the like, various digital signatures or certificates, various databases, or history information. The wide area communication unit  114  is communication means for exchanging information with an external system and server via the wide area network  2 . 
     The control unit  115  is control means for controlling operation of each structural element included in the local power management system  1 . The display unit  116  is display means for displaying information relating to power consumed in the local power management system  1 , the user information, the billing information, other types of information relating to power management, information relating to power management outside the local power management system  1 , information relating to power trading, and the like. Additionally, as the display means, an LCD, an ELD or the like is used, for example. The input unit  117  is input means for a user to input information. Additionally, as the input unit  117 , a keyboard, a button, or the like is used, for example. Furthermore, it is also possible to construct a touch panel by combining the display unit  116  and the input unit  117 . The service providing unit  118  is means for realizing, at the power management apparatus  11 , various services and functions and providing the same to a user while operating in concert with an external system, server, or the like. 
     As described, the power management apparatus  11  includes the communication means (the local communication unit  111 , the wide area communication unit  114 ) for exchanging information with an appliance, an apparatus, a system, a server, or the like, within or outside the local power management system  1 . Furthermore, the power management apparatus  11  includes the control means (the control unit  115 ) for controlling an appliance or an apparatus within the local power management system  1 . Also, the power management apparatus  11  includes information management means (the information management unit  112 ) that gathers information from an appliance, an apparatus, a system, a server, or the like, within or outside the local power management system  1 , and provides a service or authenticates an appliance or an apparatus within the local power management system  1  by using the information. Also, the power management apparatus  11  includes the display means (the display unit  116 ) for displaying information relating to power within or outside the local power management system  1 . 
     To safely and efficiently manage power within the local power management system  1 , first, an appliance, an apparatus, or the like, within the local power management system  1  has to be correctly identified. Also, to safely and efficiently manage power within the local power management system  1 , analysis of the information relating to power within and outside the local power management system  1  and performance of appropriate power control are also necessary. The function of the information management unit  112  is used for management of information performed to fulfill the above. Accordingly, the function of the information management unit  112  will be described in greater detail. Additionally, the function of the control unit  115  is used for control of a specific appliance, apparatus, or the like. 
     Details of Function 
     In the following, a functional configuration of the information management unit  112  will be described in detail with reference to  FIGS. 8 and 9 .  FIG. 8  shows a detailed functional configuration of the information management unit  112 .  FIG. 9  shows a main function of each structural element of the information management unit  112 . 
     As shown in  FIG. 8 , the information management unit  112  includes an appliance management unit  1121 , a power trading unit  1122 , an information analyzing unit  1123 , a display information generating unit  1124 , and a system management unit  1125 . 
     Appliance Management Unit  1121   
     As shown in  FIG. 9 , the appliance management unit  1121  is means for managing an appliance, an apparatus, or the like, within the local power management system  1 . For example, the appliance management unit  1121  performs, for the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the outlet expansion apparatus  127 , or the like, registration, authentication, management of an appliance ID, management of operation settings and service settings, grasping of an operational state and a usage state, gathering of environmental information, and the like. Additionally, gathering of environmental information is carried out by using the environmental sensor  131  installed in the managed block  12 . Moreover, the environmental information is information relating to temperature, humidity, weather, wind direction, wind velocity, landform, region, weather forecast, and the like, and information obtained by analysis thereof. 
     Power Trading Unit  1122   
     As shown in  FIG. 9 , the power trading unit  1122  performs acquisition of market trading data or individual trading data in the electricity market, timing control of execution of trading, execution of trading, management of trade log, and the like. Additionally, the market trading data is information relating to market price and trading conditions in the electricity market. Moreover, the individual trading data is information relating to transaction price and trading conditions determined at the time of an individual trade between a power supplier and a neighborhood consumer or the like. The timing control of execution of trading is automatic control of placing a buy order for a predetermined amount at a timing the power purchase price falls below a predetermined value or placing a sell order for a predetermined amount at a timing the power sell price rises above a predetermined value, for example. 
     Information Analyzing Unit  1123   
     As shown in  FIG. 9 , the information analyzing unit  1123  performs analysis of power generation data, analysis of power storage data, learning of life pattern, and analysis of power consumption data. Furthermore, the information analyzing unit  1123  performs, based on the analyses, estimation of power consumption pattern, estimation of power storage pattern, estimation of power discharge pattern, and estimation of power generation pattern. Additionally, analysis and learning by the information analyzing unit  1123  are performed by using time-series data of the amount of power generation by the first power generating apparatus  129  or the second power generating apparatus  130  within the local power management system  1 , time-series data of charge/discharge amount or power storage amount of the power storage apparatus  128 , or time-series data of the amount of power supplied from the power supplier system  5 , for example. 
     Furthermore, estimation by the information analyzing unit  1123  is performed by using, as data for learning, the time-series data or an analysis result obtained by analyzing the time-series data, and by using an estimation formula obtained based on a predetermined machine learning algorithm. For example, by using a genetic learning algorithm (see JP-A-2009-48266, for example), the estimation formula can be automatically constructed. Also, by inputting the past time-series data or analysis result to the estimation formula, an estimation result can be obtained. Furthermore, by sequentially inputting calculated estimation results to the estimation formula, time-series data can be estimated. 
     Furthermore, the information analyzing unit  1123  performs calculation of present or future CO 2  emissions, calculation of power supply pattern for reducing the power consumption (power saving pattern), calculation of power supply pattern for reducing CO 2  emissions (low CO 2  emissions pattern), and calculation or recommendation of appliance configuration, appliance arrangement or the like capable of reducing the power consumption and the CO 2  emissions in the local power management system  1 . The CO 2  emissions are calculated based on the total power consumption or the power consumption distinguished for each power generation method. 
     In the case of using the total power consumption, approximately average CO 2  emissions are calculated. On the other hand, in the case of using the power consumption distinguished for each power generation method, comparatively accurate CO 2  emissions are calculated. Additionally, by at least distinguishing between power supplied from the outside, power generated by the first power generating apparatus  129  and power generated by the second power generating apparatus  130 , more accurate CO 2  emissions can be calculated than when the total power consumption is used. Tax, such as carbon tax, and billing are, in many cases, determined according to the CO 2  emissions. Thus, it is assumed that enabling accurate calculation of the CO 2  emissions will increase a sense of fairness among users and contribute to widespread use of power generating means based on renewable energy. 
     Display Information Generating Unit  1124   
     As shown in  FIG. 9 , the display information generating unit  1124  generates display information to be displayed on the display unit  116 , by adjusting the format of information relating to an appliance, an apparatus or the like within the local power management system  1 , information relating to power, information relating to environment, information relating to power trading, information relating to an analysis result or an estimation result by the information analyzing unit  1123 , or the like. For example, the display information generating unit  1124  generates display information for displaying information indicating the amount of power in a graph format, or generates display information for displaying market data in a table format. Also, the display information generating unit  1124  generates a graphical user interface (GUI) used for display of various types of information or input of information. These pieces of display information generated by the display information generating unit  1124  are displayed on the display unit  116 . 
     System Management Unit  1125   
     As shown in  FIG. 9 , the system management unit  1125  performs management/update of version of firmware, which is a program for controlling basic operation of the power management apparatus  11 , restricts access thereto, and takes antivirus measures, for example. Also, in the case a plurality of power management apparatuses  11  are installed in the local power management system  1 , the system management unit  1125  exchanges information with another power management apparatuses  11 , and performs control such that a plurality of power management apparatuses  11  operate in cooperation with each other. For example, the system management unit  1125  manages the attribute (for example, priority ranks of control processes on an appliance, an apparatus, or the like) of each power management apparatus  11 . Furthermore, the system management unit  1125  performs state control of each power management apparatus  11  relating to participation in a cooperative operation or withdrawal from the cooperative operation. 
     In the foregoing, the functional configuration of the power management apparatus  11  has been described. Additionally, the functional configuration of the power management apparatus  11  described here is only an example, and functions other than the above may be added as necessary. 
     (1-3) Content Displayed on Display Unit 
     Next, the content displayed on the display unit will be described more specifically with reference to  FIGS. 10 to 13 .  FIGS. 10 to 13  are diagrams useful in explaining the content displayed on the display unit. 
     As described earlier, various information is displayed on the display unit  116  of the power management apparatus  11 . For example, as shown in  FIG. 10 , a list of appliances that have been registered in the power management apparatus  11  is displayed together with the power consumption of each appliance on the display unit of the power management apparatus  11 . Here, the power consumption may be displayed as a numeric value or, as shown in  FIG. 10 , in the form of a bar graph, for example. For an apparatus, such as an outlet expansion apparatus, to which a plurality of appliances can be connected, by selecting an “OUTLET EXPANSION APPARATUS” area on the display, it is possible to grasp the power consumption of the individual appliances connected to the outlet expansion apparatus. 
     As shown in  FIG. 11 , the display unit  116  may also display an authentication state of the appliances connected to the power management apparatus  11 . By displaying such information, it becomes possible for the user of the power management apparatus  11  to easily distinguish which appliances have been authenticated, which can increase the efficiency of user maintenance. 
     In addition, as shown in  FIG. 12 , a list of power consumption and billed amounts for each usage location may be displayed on the display unit  116 . By displaying such information, it is possible for the user to easily grasp whether standby power is being unnecessarily consumed, for example. 
     As shown in  FIG. 13 , it is also possible to distinguish between the types of power that have been used (that is, whether the power is power used outside the system or power used within the system) in the display of power consumption on the display unit  116 . 
     (1-4) Concealing Power Consumption Pattern 
     Here, a method of concealing a power consumption pattern will be described with reference to  FIGS. 14 to 18 . 
     The power consumption pattern of the managed block  12  reflects the lifestyle pattern of the user. As one example, in the power consumption pattern illustrated in  FIG. 14 , peaks appear throughout the day. From this power consumption pattern, it can be understood that the user was at home throughout the day. Also since the consumption peaks have mostly vanished by around 0:00 (midnight), it can be understood that the user went to bed at around midnight. Meanwhile, in the power consumption pattern illustrated in  FIG. 15 , although large peaks appear around 7:00 and at 21:00, few peaks appear at other times of the day. This power consumption pattern suggests that the user leaves the house at around 7:00 and is absent until close to 21:00. 
     In this way, the power consumption pattern reflects the lifestyle pattern of the user. If such power consumption pattern were known by a malicious third party, such third party could then misuse the power consumption pattern. As examples, the third party could attempt to enter the home while the user is out, conduct high-pressure sales visits when the user is at home, or commit a robbery while the user is asleep. 
     For this reason, it is necessary to strictly manage information on power consumption or to provide an arrangement for concealing the power consumption pattern. As described earlier, information on the amount of power supplied from the power supplier system  5  is gathered by the power information gathering apparatus  4  that is managed by the power supplier. This means that a time-series pattern on power consumption by the managed block  12  will be exposed to at least the power supplier. 
     For this reason, out of the above measures, it is preferable to provide an arrangement for concealing the power consumption pattern to prevent the lifestyle pattern of a user from being discovered by a third party. One way to conceal a power consumption pattern is to create discrepancies between the time-series pattern of the amount of power supplied from the power supplier system  5  and the user&#39;s lifestyle pattern. For example, the power supplier system  5  could supply power when the user is not at home, or the local system could stop receiving power from the power supplier system  5  when the user is at home. 
     Such measures are realized using the power storage apparatus  128 . For example, supplied power received from the power supplier system  5  when the user is not at home may be stored in the power storage apparatus  128  and power stored in the power storage apparatus  128  may be used when the user is at home to suppress the amount of power supplied from the power supplier system  5 . To further increase security, it would be preferable to carry out charging/discharging control of the power storage apparatus  128  to make the power consumption pattern a specified pattern and thereby mostly eradicate the characteristics that appear in the power consumption pattern due to the user&#39;s lifestyle pattern. 
     Averaging 
     As shown in  FIG. 16 , one conceivable example is a method that carries out charging/discharging control of the power storage apparatus  128  to make the power consumption constant. To make the power consumption a constant value, the power stored in the power storage apparatus  128  may be increased when the power consumption is below the constant value and discharging of the power storage apparatus  128  may be increased when the power consumption is above the constant value. Such control is carried out by the power management apparatus  11 . In addition to charging/discharging control of the power storage apparatus  128 , it is possible to trade power between power consumers and/or to carry out charging/discharging control using a battery of the electric vehicle  124  or the like. In this way, by making the power consumption constant, it is possible to eradicate the characteristics that appear in the power consumption pattern due to the user&#39;s lifestyle pattern. As a result, it is possible to eradicate the risk of the user suffering from criminal behavior due to misuse of a power consumption pattern. 
     Complicating 
     Note that so long as there is a discrepancy between the power consumption pattern and the lifestyle pattern, it is not necessary to set the power consumption at a constant value. To make the power consumption a constant value, a power storage apparatus  128  with sufficient capacity to absorb peaks in power consumption would be necessary. However, a power storage apparatus  128  with such large capacity is costly and it is not realistic to provide such an apparatus in an ordinary household merely to conceal a power consumption pattern. For this reason, a method of creating a discrepancy between the power consumption pattern and the lifestyle pattern using a power storage apparatus  128  of smaller capacity is preferable. As shown in  FIG. 17 , one conceivable example of such a method complicates (i.e., increases the complexity of) the power consumption pattern. 
     One conceivable method of complicating a power consumption pattern so as to produce comparatively small peaks and troughs throughout the pattern is described below. Although a large-capacity power storage apparatus  128  would be necessary to suppress a large peak to close to the average value, comparatively small peaks can be generated and moved using a storage apparatus with much smaller capacity. Although it is possible to complicate a power consumption pattern in units of one day, it is also effective to complicate a power consumption pattern so as to produce a different power consumption pattern every day and/or to eradicate cycles based on days of the week or month. An arrangement that complicates of the timing of events such as going out, coming home, going to bed, and getting up that are especially liable to misuse is also capable of sufficiently suppressing dishonest behavior without excessively complicating charging/discharging control of the power storage apparatus  128 . 
     Patternizing 
     Also, as shown in  FIG. 18 , a method that controls the power consumption pattern so as to substantially match the average pattern in the neighborhood is also conceivable. The average pattern in the neighborhood is obtained based on the lifestyle patterns of other people. This means that little power control should be necessary to make the power consumption pattern of a specific user match the average pattern in the neighborhood. Compared to when the power consumption is controlled to become a constant value, it should be possible to conceal the lifestyle pattern of a specific user using a power storage apparatus  128  of low capacity. When power consumption is controlled in this way, power information is exchanged between power management apparatuses  11  in the neighborhood. The average pattern in the neighborhood is calculated using the functions of the information analyzing unit  1123  or the functions of the analysis server  34 . Charging/discharging control is implemented for the power storage apparatus  128  based on the calculated average pattern. 
     (1-5) Various Control by Power Management Apparatus 
     Various control operations carried out by the power management apparatus  11  of the local power management system  1  described above will now be described in brief with reference to  FIG. 19 .  FIG. 19  is a diagram useful in explaining an overview of various control by the power management apparatus. 
     The power management apparatus  11  carries out control as shown in  FIG. 19  over the power distribution apparatus  121 , the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the outlet expansion apparatus  127 , and the like that are to be managed. That is, the power management apparatus  11  carries out various control operations over the appliances to be managed, such as power storage control, averaging control, trading control, power supply switching control, abnormality switching control, restoration control, authentication/registration control, information gathering/information processing control, external access control, and service linking control. Out of such control, charging control is control relating to power usage and storage, such as using power generated by various types of power generating apparatuses within a managed block during the day and using external power during the night. 
     As illustrated in  FIG. 19 , the power management apparatus  11  implements such control by referring to information relating to power sources, information relating to priority rankings, information relating to control conditions (parameters), and the like. 
     As shown in  FIG. 19 , for example, the information relating to power sources is information relating to power sources that the local power management system  1  to which the power management apparatus  11  belongs is capable of using. As illustrated in  FIG. 19 , such power sources can be roughly classified into external power and household power (or “system internal power”). The external power is power supplied from outside the local power management system  1 , and as one example may be standard power supplied from a power supplying company or the like. System internal power is power managed inside the local power management system  1 , and as examples may be power stored in the power storage apparatus, power generated by a power generating apparatus, power stored in the electric vehicle, and power stored in a battery module. Note that the expression “power stored in the power storage apparatus” here refers not only to power stored in a so-called dedicated power storage apparatus but also includes power stored in a battery or the like provided in an apparatus that is capable of being controlled by the power management apparatus  11 , such as a computer, a household electrical appliance, or a mobile telephone. The power management apparatus  11  is also capable of using such information to store information showing which power source supplied the power stored in the power storage apparatus. 
     As shown in  FIG. 19 , for example, the information relating to priority rankings is information setting priority rankings for supplying power. If the supplying of power stops to a refrigerator that functions to keep food and drink fresh or a security-related appliance that maintains security in the system, or if power used for lighting or controlling appliances stops, it may become difficult to achieve such functions, which can adversely affect the user. Accordingly, the power management apparatus  11  is capable of supplying unrestricted power to such appliances to guarantee that such functions are maintained. The power management apparatus  11  is also capable of suppressing power usage by appropriately controlling the supplying of power to appliances (such as a television or air conditioner) whose priority ranking is set at “POWER SAVING MODE”. The power management apparatus  11  is also capable of setting a “POWER OFF” priority ranking, and as one example it is possible to implement control so that the power of a recharger is normally off. Note that the priority rankings shown in  FIG. 19  are mere examples and the priority rankings provided in the power management apparatus  11  are not limited to the examples shown in  FIG. 19 . 
     As shown in  FIG. 19 , for example, the information relating to control conditions is information setting the control conditions of the power management apparatus  11 . As one example, such control conditions are roughly classified into conditions relating to the usage environment of power, conditions relating to the usage period of power, conditions relating to power usage mode, and conditions relating to abnormalities, for example. As shown in  FIG. 19 , it is possible to set more detailed condition items for the respective conditions. Note that the control conditions shown in  FIG. 19  are mere examples and the control conditions provided in the power management apparatus  11  are not limited to the examples shown in  FIG. 19 . 
     Based on such information, the power management apparatus  11  implements control as shown in  FIG. 19  over the respective appliances in the system  1 . By doing so, the power management apparatus  11  is capable of carrying out charging control over the respective appliances being managed, controlling the operation of appliances, and updating the firmware of devices. For example, the power management apparatus  11  is capable of carrying out control such as “Start function of rice cooker at XX o&#39;clock”. It is also possible to link such control to a power estimating function that is another function provided in the power management apparatus  11  and start functions during a time zone where power is cheap. The power management apparatus  11  is also capable of operating in concert with a server provided outside the system  1  so as to provide a variety of services to a user. For example, an externally provided server is capable of using output information outputted by the power management apparatus  11  to provide services and the like that make it possible to easily check whether family members who live apart have a normal power usage state (that is, such family members are living as normal with no health problems). 
     Such control is capable of being implemented by not only the power management apparatus  11  but also by the control-compliant outlet  123 , the outlet expansion apparatus  127 , and the like provided in the power management system  1 , for example. 
     To carry out such control, the power management apparatus  11  stores information such as the information shown in  FIG. 20  and also registers such information in the system management server  33  provided outside the system  1 .  FIG. 20  is a diagram useful in explaining various information managed by the power management apparatus  11 . 
     As illustrated in  FIG. 20 , the power management apparatus  11  stores information such as an identification number (ID) assigned to the apparatus, information relating to the manufacturer, model number, and the like, a date of registration in the system, and a status. In addition, the power management apparatus  11  stores information such as the user name, address, telephone number, billing information (information relating to a bank account and the like), and emergency contact of the user who owns the power management apparatus  11 . The power management apparatus  11  also stores information relating to an ID, manufacturer name, model number, registration date, status, and the like assigned to the power distribution apparatus  121  present in the system  1 . In addition, the power management apparatus  11  stores information relating to an ID, manufacturer name, model number, registration date, status, and the like assigned to the various types of control-compliant appliance  125  present in the system  1 . 
     By storing such information, it becomes possible for the power management apparatus  11  to send requests for acquisition of various information and/or for the provision of various services to a server provided outside the system  1 . For example, the power management apparatus  11  is capable of referring to manufacturer information for a certain control-compliant appliance  125 , accessing a server managed by such manufacturer, and acquiring various information relating to the control-compliant appliance  125  from the accessed server. 
     Note that aside from the control-compliant appliances  125  (i.e., the power distribution apparatus  121 , the control-compliant outlet  123 , the electric vehicle  124 , the outlet expansion apparatus  127 , the power storage apparatus  128 , and the power generating apparatuses  129 ,  130 ) that are capable of being controlled by the power management apparatus  11 , there are also cases where non-control-compliant appliances and/or non-control compliant outlets that are apparatuses that are not capable of being controlled are present in the local power management system  1 . For this reason, the power management apparatus  11  selects the method of exchanging information, the method of controlling power supply, and the like in accordance with what type of apparatus (control-compliant appliance or non-control-compliant appliance) is connected to what type of outlet (control compliant outlet or non-control compliant outlet). Note that as described below, unless stated otherwise, the expression “control-compliant appliance  125 ” also includes appliance types that can be controlled, such as the control-compliant outlet  123 , the electric vehicle  124 , the outlet expansion apparatus  127 , the power storage apparatus  128 , and the like. 
       FIG. 21  is a diagram useful in explaining combinations of communication means, authentication means, and power supplying control set in accordance with the type of outlet and type of connected appliance. As should be clear from  FIG. 21 , the combinations of a type of outlet and a type of connected appliance connected to such outlet are roughly classified into four patterns. 
     When a control-compliant appliance  125  is connected to a control-compliant outlet  123 , the power management apparatus  11  is capable of communication with and control over both the control-compliant outlet  123  and the control-compliant appliance  125 . Accordingly, when a connected appliance transmits power information to the power management apparatus  11 , the connected appliance (that is, the control-compliant appliance  125 ) may transmit the power information to the power management apparatus  11  using ZigBee, for example. The control-compliant outlet  123  may use ZigBee or PLC, for example, to transmit power information to the power management apparatus  11 . In addition, during authentication of a connected appliance, the connected appliance (control-compliant appliance  125 ) is capable of using ZigBee, for example, to carry out authentication with the power management apparatus  11 . Regarding control over the supplying of power to a connected appliance, it is possible for the power management apparatus  11  to transmit a control command to the power distribution apparatus  121 . In some cases, it is also possible for the control-compliant outlet  123  to carry out limited control over the supplying of power to a connected appliance. 
     When a non-control-compliant appliance  126  is connected to a control-compliant outlet  123 , it may not be possible for the connected appliance to carry out the authentication process with the power management apparatus  11 . This means that in this case, there is no way for the connected appliance and the power management apparatus  11  to carry out appliance authentication. The communication of power information in this case may be carried out via ZigBee or PLC, for example, from the control-compliant outlet  123  to which the non-control-compliant appliance  126  is connected. Regarding control over the supplying of power to the connected appliance, it is possible for the power management apparatus  11  to transmit control commands to the power distribution apparatus  121 . Also, in some cases, it is possible for the control-compliant outlet  123  to carry out limited control over the supplying of power to the connected appliance. 
     When a control-compliant appliance  125  is connected to a non-control-compliant outlet, it is possible for the connected appliance to use ZigBee, for example, to carry out an appliance authentication process with the power management apparatus  11  and to transmit power information to the power management apparatus  11 . Also, regarding control over the supplying of power to the connected appliance, it is possible for the power management apparatus  11  to transmit control commands to the power distribution apparatus  121 . 
     When a non-control-compliant appliance  126  is connected to a non-control-compliant outlet, it may not be possible for the connected appliance to carry out the appliance authentication process with the power management apparatus  11  or to transmit power information to the power management apparatus  11 . Also, since it may not be possible to control the supplying of power to the connected appliance, the power management apparatus  11  constantly supplies power to the connected appliance. 
     (1-6) Configuration of Appliance Management Unit 
     The control over appliances described above is carried out based on various information acquired by the information management unit  112  provided in the power management apparatus  11 . The detailed configuration of an appliance management unit  1121  provided in the information management unit  112  of the power management apparatus  11  will now be described in detail with reference to  FIG. 22 .  FIG. 22  is a block diagram showing the configuration of the appliance management unit  1121  according to the present embodiment. 
     The appliance management unit  1121  mainly includes a key generating unit  1501 , a system registering unit  1503 , a managed appliance registering unit  1505 , a managed appliance information acquiring unit  1507 , a managed appliance information output unit  1509 , an excluded appliance specifying unit  1511 , an information tampering detecting unit  1513 , and a power usage certificate management unit  1515 . 
     As one example, the key generating unit  1501  may be realized by a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The key generating unit  1501  generates various types of key, such as a public key, secret key, or common key, for use in the local power management system  1  and various types of key, such as a public key, secret key, or common key for use in communication between the local power management system  1  and apparatuses provided outside the system  1 . The key generating unit  1501  uses public parameters that have been disclosed by the system management server  33  or the certificate authority server  35 , for example, to generate various parameters for use when such keys are generated or to generate the keys themselves. The key generating unit  1501  stores the generated parameters or keys securely in the storage unit  113  or the like. 
     A key generation process carried out by the key generating unit  1501  is implemented in accordance with a request from the system registering unit  1503  or the managed appliance registering unit  1505 , described later. Once the key generation process has ended, the key generating unit  1501  may output the generated key or the like to the processing unit (the system registering unit  1503  or the managed appliance registering unit  1505 ) that made the request. The key generating unit  1501  may inform the processing unit (the system registering unit  1503  or the managed appliance registering unit  1505 ) that made the request that the key generating process has ended so that the processing unit may then acquire the generated key or the like from a specific location (for example, the storage unit  113 ). 
     The protocol when the key generating unit  1501  implements the key generating process is not limited to a specified protocol, and it is possible to use a protocol set within the local power management system  1  or decided by agreement with a server, for example. 
     The system registering unit  1503  is realized by a CPU, a ROM, a RAM, and the like, for example. The system registering unit  1503  is a processing unit that carries out processing that registers, via the wide area communication unit  114 , the power management apparatus  11  itself in the system management server  33  that manages the local power management system  1 . 
     The system registering unit  1503  first connects via the wide area communication unit  114  to the system management server  33  and implements a specific authentication process with the system management server  33 . Next, the system registering unit  1503  transmits specified registration information to the system management server  33  to register the power management apparatus  11  itself in the system management server  33 . 
     One example of the registration information that the system registering unit  1503  transmits to the system management server  33  is the information shown in  FIG. 20 . 
     A specific example of the registration process implemented by the system registering unit  1503  will be described in detail later. 
     The managed appliance registering unit  1505  is realized by a CPU, a ROM, a RAM, and the like, for example. The managed appliance registering unit  1505  carries out communication with the control-compliant outlet  123 , the electric vehicle  124 , the control-compliant appliance  125 , the outlet expansion apparatus  127 , the power storage apparatus  128 , the power generating apparatuses  129 ,  130 , and the like that are capable of communicating via the local communication unit  111  and registers appliances with which communication has been established as managed appliances. When such control-compliant apparatuses are connected to a power point (the control-compliant outlet  123 , the outlet expansion apparatus  127 , the non-control-compliant outlet) and/or are switched on, the managed appliance registering unit  1505  carries out a specified authentication process with such apparatuses and carries out a specified registration process after authentication. 
     The managed appliance registering unit  1505  acquires information on an identification number (appliance ID) that is unique to the apparatus, a manufacturer name, a model number, power usage, an ID of a connected outlet, and the like as registration information from a control-compliant apparatus. The managed appliance registering unit  1505  registers the acquired registration information in a database that is stored in the storage unit  113  or the like. The managed appliance registering unit  1505  also transmits the acquired registration information via the wide area communication unit  114  to the system management server  33  to register the information in the system management server  33 . 
     The detailed configuration of the managed appliance registering unit  1505  will be described in more detail later. A specific example of the registration process that is implemented by the managed appliance registering unit  1505  will also be described in detail later. 
     The managed appliance information acquiring unit  1507  is realized by a CPU, a ROM, a RAM, and the like, for example. The managed appliance information acquiring unit  1507  acquires various information via the local communication unit  111  from managed appliances registered in the power management apparatus  11 . As shown in  FIG. 8 , for example, information showing the operation state of an appliance, information showing the usage state of the appliance, environmental information, power information, and the like can be given as examples of the information acquired from a managed appliance. The managed appliance information acquiring unit  1507  is also capable of acquiring various information aside from the information mentioned above from a managed appliance. 
     The managed appliance information acquiring unit  1507  is also capable of transferring the various information acquired from a managed appliance to the managed appliance information output unit  1509  and the excluded appliance specifying unit  1511 , described later. If the appliance management unit  1121  includes the information tampering detecting unit  1513 , the managed appliance information acquiring unit  1507  may transfer the various information acquired from a managed appliance to the information tampering detecting unit  1513 . 
     The managed appliance information output unit  1509  is realized by a CPU, a ROM, a RAM, and the like, for example. The managed appliance information output unit  1509  outputs the various information that the managed appliance information acquiring unit  1507  has acquired from a managed appliance to a specified processing unit of the power management apparatus  11  and/or outputs the information via the wide area communication unit  114  to an apparatus provided outside the power management apparatus  11 . Also, as described later, if a managed appliance embeds data for detecting whether information has been tampered with into the information, the managed appliance information output unit  1509  acts as a mediator when such information in which the data has been embedded is transferred to the analysis server  34 . 
     The excluded appliance specifying unit  1511  is realized by a CPU, a ROM, a RAM, and the like, for example. The excluded appliance specifying unit  1511  specifies managed appliances to be excluded from the local power management system  1  based on the various information obtained by the managed appliance information acquiring unit  1507  from the managed appliances. The excluded appliances may be decided based on various information that has been acquired or may be decided based on an inability to acquire information that should normally be available. The method of specifying the excluded appliances is not limited to a specific method and it is possible to use an arbitrary method. 
     The information tampering detecting unit  1513  is realized by a CPU, a ROM, a RAM, and the like, for example. If data for detecting whether the information has been tampered with is embedded in the information acquired by the managed appliance information acquiring unit  1507  from a managed appliance, the information tampering detecting unit  1513  verifies such data and detects whether the information has been tampered with. An electronic watermark can be given as one example of such data embedded in the information. 
     On detecting that the information has been tampered with, the information tampering detecting unit  1513  may inform the excluded appliance specifying unit  1511  of such result. By doing so, the excluded appliance specifying unit  1511  becomes able to exclude an appliance where tampering with information has occurred from the system  1 . 
     The tampering detection process implemented by the information tampering detecting unit  1513  will be described in detail later. 
     The power usage certificate management unit  1515  is realized by a CPU, a ROM, a RAM, and the like, for example. In the local power management system  1  that includes the power management apparatus  11 , in some cases power may be supplied to a control-compliant appliance  125  or the like that does not belong to the system  1 . To do so, as described below, the control-compliant appliance  125  or the like from outside the system  1  in which the supplying of power was received issues a power usage certificate to the power management apparatus  11  that manages the system in which the supplying of power was received. A power usage certificate is a certificate that has a specific format that shows that the supplying of power has been received. The power usage certificate management unit  1515  manages the issued power usage certificates and verifies whether the issued power usage certificates are official certificates. When an issued power usage certificate is an official certificate, the power usage certificate management unit  1515  is capable of using the power usage certificate to carry out control over billing relating to the supplied power. 
     The process carried out by the power usage certificate management unit  1515  will be described in detail later. 
     Configuration of Managed Appliance Registering Unit 
     Next, the configuration of the managed appliance registering unit  1505  will be described in detail with reference to  FIG. 23 .  FIG. 23  is a block diagram useful in explaining the configuration of the managed appliance registering unit  1505 . 
     As shown in  FIG. 23 , the managed appliance registering unit  1505  includes a managed appliance authentication unit  1551 , a signature generating unit  1553 , and a signature verifying unit  1555 . 
     The managed appliance authentication unit  1551  is realized by a CPU, a ROM, a RAM, and the like, for example. If a control-compliant appliance  125  or the like that is not registered in the local power management system  1  managed by the power management apparatus  11  is connected, the managed appliance authentication unit  1551  uses the key or the like generated by the key generating unit  1501  to authenticate the control-compliant appliance  125  or the like that is not registered. This authentication process may be a public key authentication process using a public key or may be a common key authentication process using a common key. By acting in concert with the signature generating unit  1553  and the signature verifying unit  1555  described later, the managed appliance authentication unit  1551  carries out the authentication process and registration process for the managed appliance. 
     The signature generating unit  1553  is realized by a CPU, a ROM, a RAM, and the like, for example. The signature generating unit  1553  uses the key or the like generated by the key generating unit  1501  to generate a specific signature (digital signature) and/or certificate for the control-compliant appliance  125  or the like that is carrying out the authentication process. The signature generating unit  1553  registers information relating to the generated signature and/or certificate in a database stored in the storage unit  113  or the like and transmits the generated signature and/or certificate via the local communication unit  111  to the control-compliant appliance  125  or the like that is carrying out the authentication process. 
     The signature verifying unit  1555  is realized by a CPU, a ROM, a RAM, and the like, for example. The signature verifying unit  1555  uses the key or the like generated by the key generating unit  1501  to verify the signature (digital signature) and/or certificate transmitted to the power management apparatus  11  by the control-compliant appliance  125  or the like that is carrying out the authentication process. If the verification of the signature and/or certificate has succeeded, the signature verifying unit  1555  registers information relating to the signature and/or certificate for which verification succeeded in a database stored in the storage unit  113  or the like. If the verification of the signature and/or certificate has failed, the signature verifying unit  1555  may cancel the authentication process. 
     A specific example of the authentication process and registration process implemented on a managed appliance by the managed appliance registering unit  1505 , the managed appliance authentication unit  1551 , the signature generating unit  1553 , and the signature verifying unit  1555  acting in concert will be described in detail later. 
     Configuration of Information Tampering Detecting Unit 
     Next, the configuration of the information tampering detecting unit  1513  will be described in detail with reference to  FIG. 24 .  FIG. 24  is a block diagram useful in explaining the configuration of the information tampering detecting unit  1513 . 
     As shown in  FIG. 24 , the information tampering detecting unit  1513  also includes an embedded position specifying unit  1561 , an electronic watermark extracting unit  1563 , and an electronic watermark verifying unit  1565 . 
     With the local power management system  1  according to the present embodiment, it is possible to embed, into physical data such as current, voltage, temperature, and humidity, or into various information calculated using such physical data, electronic watermark data that is suited to such information. By verifying the electronic watermark data, apparatuses in the local power management system  1  and various types of server that are capable of two-way communication with the local power management system  1  are capable of detecting whether the physical data (which hereinafter includes various information calculated using physical data) has been tampered with. 
     The embedded position specifying unit  1561  is realized by a CPU, a ROM, a RAM, and the like, for example. By analyzing the physical data in which the electronic watermark has been embedded using a predetermined signal processing circuit, the embedded position specifying unit  1561  specifies the embedded position of the electronic watermark information in accordance with the characteristics of a signal corresponding to the data. On specifying the embedded position of the electronic watermark information, the embedded position specifying unit  1561  informs the electronic watermark extracting unit  1563  of information relating to the specified embedded position. Note that if the embedded position of the electronic watermark is determined in advance between a control-compliant appliance  125  or the like and the power management apparatus  11 , it may not be necessary to carry out the specifying process for the embedded position. 
     The electronic watermark extracting unit  1563  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark extracting unit  1563  extracts the electronic watermark information from the physical data based on information relating to the embedded position provided by the embedded position specifying unit  1561 . The electronic watermark extracting unit  1563  transfers the electronic watermark extracted from the physical data to the electronic watermark verifying unit  1565 , described later. 
     The electronic watermark verifying unit  1565  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark verifying unit  1565  first generates electronic watermark information based on shared information shared with the control-compliant appliance  125  or the like and physical data extracted by the electronic watermark extracting unit  1563 . To generate the electronic watermark information, a hash function, a pseudorandom number generator, public key encryption, common key encryption, another encryption primitive (for example, a message authentication code (MAC)), or the like is used. After this, the electronic watermark verifying unit  1565  compares the generated electronic watermark information and the electronic watermark information extracted by the electronic watermark extracting unit  1563 . 
     If the generated electronic watermark information and the extracted electronic watermark information are the same, the electronic watermark verifying unit  1565  judges that the physical data or the like generated by the control-compliant appliance  125  or the like has not been tampered with. Meanwhile, if the generated electronic watermark information and the extracted electronic watermark information are not the same, the electronic watermark verifying unit  1565  judges that the physical data has been tampered with. 
     If the physical data has been tampered with, the electronic watermark verifying unit  1565  informs the excluded appliance specifying unit  1511 . By doing so, the excluded appliance specifying unit  1511  becomes able to exclude a control-compliant appliance  125  or the like whose operation may have been modified from the local power management system  1 . 
     This completes the detailed description of the configuration of the appliance management unit  1121 . 
     (1-7) Configuration of Information Analyzing Unit 
     Next, the configuration of the information analyzing unit  1123  will be described in detail.  FIG. 25  is a block diagram useful in explaining the configuration of the information analyzing unit. 
     The information analyzing unit  1123  is a processing unit that generates secondary information, such as that shown in  FIG. 8 , which is an analysis result of various data and is based on information acquired by or generated by the appliance management unit  1121 . As shown in  FIG. 25 , for example, the information analyzing unit  1123  includes an appliance state judging unit  1601  and a power state judging unit  1603 . 
     The appliance state judging unit  1601  is realized by a CPU, a ROM, a RAM, and the like, for example. Based on various managed appliance information acquired by the appliance management unit  1121 , the appliance state judging unit  1601  judges the appliance states of the respective managed appliances. When, as a result of the judging, the state of a managed appliance is judged to be abnormal, the appliance state judging unit  1601  informs the user of the abnormality via the display unit  116  and also requests the control unit  115  to control the managed appliance judged to be in the abnormal state. 
     The power state judging unit  1603  is realized by a CPU, a ROM, a RAM, and the like, for example. The power state judging unit  1603  judges the power state in the local power management system  1  whose power state is managed by the power management apparatus  11  based on the power information obtained by the appliance management unit  1121  from various apparatuses. When, as a result of the judging, the state of a managed appliance is judged to be abnormal, the power state judging unit  1603  informs the user of the abnormality via the display unit  116  and also requests the control unit  115  to control the managed appliance judged to be in the abnormal state. 
     This completes the description of one example of the functions of the power management apparatus  11  according to the present embodiment. The various component elements described above may be configured using general-purpose parts and circuits or may be configured using hardware that is dedicated to the functions of the respective component elements. Alternatively, the functions of the respective component elements may all be carried out by a CPU or the like. Accordingly, it is possible to change the configuration in use as appropriate in accordance with the prevailing technical level when implementing the present embodiment. 
     Note that a computer program for realizing the functions of the power management apparatus according to the above embodiment may be created and installed in a personal computer or the like. It is also possible to provide a computer-readable recording medium on which such a computer program is stored. As examples, the recording medium may be a magnetic disk, an optical disc, a magneto-optical disc, or a flash memory. The computer program mentioned above may also be distributed via a network, for example, without using a recording medium. 
     (1-8) Configuration of Control-Compliant Appliance 
     Next, the configuration of a control-compliant appliance according to the present embodiment will be described in detail with reference to  FIG. 26 .  FIG. 26  is a block diagram useful in explaining the configuration of a control-compliant appliance according to the present embodiment. 
     As illustrated in  FIG. 26 , the control-compliant appliance  125  mainly includes a control unit  2001 , a sensor  2003 , a battery  2005 , a function providing unit  2007 , a local communication unit  2009 , an input unit  2011 , a display unit  2013 , a storage unit  2015 , and the like. 
     The control unit  2001  is realized by a CPU, a ROM, a RAM, and the like, for example. The control unit  2001  is a processing unit that carries out execution control over processing units provided in the control-compliant appliance  125 . As described earlier, the control unit  2001  also transmits primary information and the like relating to the control-compliant appliance  125  to the power management apparatus  11 . In addition, when the supplying of power has been received from a power management appliance in which the control-compliant appliance  125  is temporarily registered, the control unit  2001  generates a power usage certificate as described later. Note that the configuration of the control unit  2001  will be described in detail later. 
     The sensor  2003  is composed of a current sensor or voltage sensor that monitors the state of a battery or a sensor capable of acquiring various physical data, such as a temperature sensor, humidity sensor, barometer, or the like that monitors the peripheral environment at the setup location of the control-compliant appliance  125 . Based on control by the control unit  2001 , the sensor  2003  measures various physical data at specified time intervals or at arbitrary timing and outputs the obtained physical data to the control unit  2001  as sensor information. 
     The battery  2005  is a power storage apparatus provided in the control-compliant appliance  125 , is composed of one or a plurality of cells, and supplies the power necessary for the control-compliant appliance  125  to operate. Power is supplied to the battery  2005  by external power or the power generating apparatuses  129 ,  130  present in the system  1  and is stored in the battery  2005 . The battery  2005  is controlled by the control unit  2001  and outputs various physical data to the control unit  2001  as battery information at specified time intervals or at arbitrary timing. 
     Note that although  FIG. 26  shows an example where the control-compliant appliance  125  is equipped with the battery  2005 , depending on the type of control-compliant appliance  125 , a configuration may be used where no battery  2005  is provided and power is supplied directly to the control-compliant appliance  125 . 
     The function providing unit  2007  is realized by a CPU, a ROM, a RAM, and various devices or the like, for example. The function providing unit  2007  is a processing unit that realizes a specified function (for example, a rice cooking function, a refrigeration function, or a function that records and executes various content) provided by the control-compliant appliance  125  to the user. The function providing unit  2007  provides such functions to the user based on control by the control unit  2001 . 
     The local communication unit  2009  is realized by a CPU, a ROM, a RAM, and a communication apparatus or the like, for example. The local communication unit  2009  is communication means for communicating via a communication network constructed inside the local power management system  1 . The local communication unit  2009  is capable of communicating with the power management apparatus  11  according to the present embodiment via the communication network constructed inside the local power management system  1 . 
     The input unit  2011  is realized by a CPU, a ROM, a RAM, and an input apparatus or the like, for example. The input unit  2011  is an input device for enabling the user to input information. Note that as examples, a keyboard, buttons, or the like is used as the input unit  2011 . It is also possible to combine the display unit  2013 , described later, and the input unit  2011  to construct a touch panel. 
     The display unit  2013  is realized by a CPU, a ROM, a RAM, and an output apparatus or the like, for example. The display unit  2013  is a display device for displaying information relating to power consumption by the control-compliant appliance  125 , user information, billing information, other information relating to power management, information relating to power management outside the local power management system  1 , information relating to power trading, and the like. Note that as examples, an LCD, an ELD, or the like is used as the display device. 
     The storage unit  2015  is one example of a storage apparatus provided in the control-compliant appliance  125 . The storage unit  2015  stores identification information that is unique to the control-compliant appliance  125 , information relating to various keys held by the control-compliant appliance  125 , various digital signatures and/or certificates held by the control-compliant appliance  125 , and the like. Various history information may also be recorded in the storage unit  2015 . In addition, various parameters and intermediate progress of processing that should be stored when the control-compliant appliance  125  according to the present embodiment carries out processing or various databases or the like are recorded as appropriate in the storage unit  2015 . The various processing units of the control-compliant appliance  125  are also capable of freely reading from and writing into the storage unit  2015 . 
     Configuration of Control Unit—Part 1 
     This completes the description of the overall configuration of a control-compliant appliance  125  according to the present embodiment. The configuration of the control unit  2001  of a control-compliant appliance  125  will now be described in detail with reference to  FIG. 27 . 
     As illustrated in  FIG. 27 , the control unit  2001  of a control-compliant appliance  125  includes an authentication processing unit  2021 , a sensor control unit  2023 , a sensor information output unit  2025 , a battery control unit  2027 , and a battery information output unit  2029 . 
     The authentication processing unit  2021  is realized by a CPU, a ROM, a RAM, and the like, for example. The authentication processing unit  2021  carries out an authentication process together with the power management apparatus  11  based on a specified protocol and also carries out processing that registers a control-compliant appliance  125  in the power management apparatus  11 . When carrying out processing with the power management apparatus  11 , the authentication processing unit  2021  is capable of using the various keys stored in the storage unit  2015  or the like, digital signatures or certificates provided by the manufacturer when the control-compliant appliance  125  was manufactured, and various parameters and the like. The authentication process implemented by the authentication processing unit  2021  is not limited to any specified process and it is possible to use any arbitrary process in accordance with the content and configuration of the system  1 . 
     The sensor control unit  2023  is realized by a CPU, a ROM, a RAM, and the like, for example. The sensor control unit  2023  is a processing unit that controls the sensor  2003  provided in the control-compliant appliance  125 . The sensor control unit  2023  carries out control over the sensor  2003  according to a specified method, acquires physical data measured by the sensor  2003  at specified time intervals or at arbitrary timing and outputs the physical data to the sensor information output unit  2025 , described later. 
     The sensor information output unit  2025  is realized by a CPU, a ROM, a RAM, and the like, for example. The sensor information output unit  2025  outputs sensor information outputted from the sensor control unit  2023  via the local communication unit  2009  to the power management apparatus  11 . The sensor information output unit  2025  may also implement preprocessing, such as a noise reduction process and a digitizing process, when outputting the sensor information. The sensor information output unit  2025  may use the information acquired from the sensor control unit  2023  to generate various types of secondary information and output such information as sensor information. 
     The battery control unit  2027  is realized by a CPU, a ROM, a RAM, and the like, for example. The battery control unit  2027  is a processing unit that controls the battery  2005  provided in the control-compliant appliance  125 . The battery control unit  2027  uses the power stored in the battery  2005  to cause the control-compliant appliance  125  to function and depending on the state, supplies the power stored in the battery  2005  to outside the control-compliant appliance  125 . The battery control unit  2027  carries out control over the battery  2005  according to a specified method, acquires physical data measured by the battery  2005  at specified time intervals or at arbitrary timing and outputs the physical data to the battery information output unit  2029 , described later. 
     The battery information output unit  2029  is realized by a CPU, a ROM, a RAM, and the like, for example. The battery information output unit  2029  outputs battery information outputted from the battery control unit  2027  via the local communication unit  2009  to the power management apparatus  11 . When outputting the battery information, the battery information output unit  2029  may also implement preprocessing, such as a noise reduction process and a digitizing process, when outputting the battery information. The battery information output unit  2029  may also generate various secondary information using information acquired from the battery control unit  2027  and output the secondary information as the battery information. 
     Configuration of Control Unit—Part 2 
     The control unit  2001  of a control-compliant appliance  125  may have the configuration described below instead of the configuration shown in  FIG. 27 . Another configuration of the control unit  2001  provided in a control-compliant appliance  125  will now be described in detail with reference to  FIG. 28 . 
     As illustrated in  FIG. 28 , the control unit  2001  of a control-compliant appliance  125  may include the authentication processing unit  2021 , the sensor control unit  2023 , the battery control unit  2027 , and a tampering detection information generating unit  2031 . 
     Since the authentication processing unit  2021  shown in  FIG. 28  has the same configuration as the authentication processing unit  2021  shown in  FIG. 27  and achieves the same effect, detailed description thereof is omitted. Similarly, aside from outputting the sensor control information and the battery information to the tampering detection information generating unit  2031 , the sensor control unit  2023  and the battery control unit  2027  shown in  FIG. 28  have the same configuration and achieve the same effects as the corresponding processing units shown in  FIG. 27 . Accordingly, detailed description thereof is omitted. 
     The tampering detection information generating unit  2031  is realized by a CPU, a ROM, a RAM, and the like, for example. The tampering detection information generating unit  2031  generates tampering detection information for use in detecting whether information has been tampered with based on the sensor information outputted from the sensor control unit  2023  and the battery information outputted from the battery control unit  2027 . The tampering detection information generating unit  2031  transmits the generated tampering detection information via the local communication unit  2009  to the power management apparatus  11 . The power management apparatus  11  may also transfer the tampering detection information generated by the tampering detection information generating unit  2031  to various servers, such as the analysis server  34 , provided outside the local power management system  1 . 
     Configuration of Tampering Detection Information Generating Unit 
     The detailed configuration of the tampering detection information generating unit  2031  will now be described with reference to  FIG. 29 .  FIG. 29  is a block diagram useful in explaining the configuration of the tampering detection information generating unit. 
     As illustrated in  FIG. 29 , the tampering detection information generating unit  2031  further includes an appliance characterizing information generating unit  2033 , an electronic watermark generating unit  2035 , an embedded position deciding unit  2037 , and an electronic watermark embedding unit  2039 . 
     The appliance characterizing information generating unit  2033  is realized by a CPU, a ROM, a RAM, and the like, for example. The appliance characterizing information generating unit  2033  generates appliance characterizing information that is characterizing amount information which characterizes the control-compliant appliance  125  based on the sensor information and the battery information outputted from the sensor control unit  2023  and the battery control unit  2027 . The appliance characterizing information generating unit  2033  may use the sensor information and the battery information themselves as the appliance characterizing information or may use information newly generated using the sensor information and the battery information as the appliance characterizing information. The appliance characterizing information generating unit  2033  outputs the generated appliance characterizing information to the embedded position deciding unit  2037  and the electronic watermark embedding unit  2039 , described later. 
     Note that the appliance characterizing information generating unit  2033  may verify the inputted sensor information and the battery information before generating the appliance characterizing information. In such case, the appliance characterizing information generating unit  2033  may refer to a database or the like stored in the storage unit  2015  or the like to acquire a range of values that can be taken by physical data such as the sensor information and the battery information and judge whether the obtained physical data is present within such range. Also, the appliance characterizing information generating unit  2033  may analyze the obtained physical data and confirm that the control-compliant appliance  125  is not exhibiting abnormal behavior. If, by carrying out such verification, the appliance characterizing information generating unit  2033  has detected abnormal behavior or that the validity of the physical data is be confirmed, the appliance characterizing information generating unit  2033  may inform the user of such state via the display unit  2013 . 
     The electronic watermark generating unit  2035  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark generating unit  2035  uses shared information, such as information relating to key information and identification numbers, that is shared between the control-compliant appliance  125  and the power management apparatus  11  or an external server such as the analysis server  34  to generate electronic watermark information to be used as tampering detection information. 
     As examples, the electronic watermark information generated by the electronic watermark generating unit  2035  can be generated using the shared information itself, a pseudorandom string generated based on the shared information, information generated using a unique value, such as ID information, that is unique to the control-compliant appliance  125 , and the like. If the method of generating and embedding the electronic watermark information or the embedding of the electronic watermark information itself are not made known to third parties, it becomes possible by using electronic watermark information generated using such information to detect tampering with the information. 
     It is also possible to transfer physical data in which electronic watermark information generated by the method described below has been embedded via the power management apparatus  11  to an external server such as the analysis server  34 . Meanwhile, there is also the risk that the power management apparatus  11  that acts as an intermediary apparatus will have been taken over by a malicious third party or the like. In such case, the third party that has taken over the power management apparatus  11  could conceivably engage in illegal behavior such as reusing tampering detection information from before the takeover to prevent genuine users, administrators of external servers, and the like from noticing the takeover. For this reason, by regularly generating the electronic watermark information using time information in addition to information such as that described above, the electronic watermark generating unit  2035  is capable of detecting developments such as the power management apparatus  11  being taken over in the manner described above. 
     To generate the electronic watermark information, the electronic watermark generating unit  2035  is capable of using a variety of techniques, such as a hash function, public key encryption, a pseudorandom number generator, common key encryption, another encryption primitive (MAC), or the like. In such case, the data size of the outputted electronic watermark information is set at m bits. 
     In this way, the electronic watermark generating unit  2035  according to the present embodiment generates the electronic watermark information using physical data and does not use the physical data itself as the electronic watermark information. 
     The electronic watermark generating unit  2035  outputs the generated electronic watermark information to the electronic watermark embedding unit  2039 , described later. 
     The embedded position deciding unit  2037  is realized by a CPU, a ROM, a RAM, and the like, for example. The embedded position deciding unit  2037  analyzes the appliance characterizing information transferred from the appliance characterizing information generating unit  2033  and determines the embedded position for the tampering detection information in the appliance characterizing information. More specifically, out of the appliance characterizing information, the embedded position deciding unit  2037  decides a region with large values that are equal to or greater than a specified threshold, a region with high dispersion, a region corresponding to a noise region, a high-frequency domain when data on a frequency domain is handled, or the like as the embedded position. If the electronic watermark information is embedded into a region in the data such as a region with high noise and a region with a high SN ratio, there is little effect on the overall tendencies (for example, the statistical properties) of the appliance characterizing information. This means that by using such regions as the embedded position of the electronic watermark information, it becomes unnecessary to transmit the electronic watermark information separately to the appliance characterizing information and possible even for a power management apparatus  11  that only has a function for receiving the appliance characterizing information to detect tampering. 
     The embedded position deciding unit  2037  outputs position information relating to the decided embedded position to the electronic watermark embedding unit  2039 , described later. Note that when the embedded position of the electronic watermark information is decided in advance, this process does not have to be carried out. 
     The electronic watermark embedding unit  2039  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark embedding unit  2039  embeds the electronic watermark information generated by the electronic watermark generating unit  2035  in the appliance characterizing information generated by the appliance characterizing information generating unit  2033  based on the position information relating to the embedded position received from the embedded position deciding unit  2037 . By doing so, appliance characterizing information in which the electronic watermark information has been embedded is generated. 
     The electronic watermark embedding unit  2039  may subject the appliance characterizing information in which the electronic watermark information has been embedded to verification once again. By carrying out such verification, it becomes possible, when the information contains values that exceed a range of values that can be taken by the appliance characterizing information or when abnormal behavior is clearly indicated, for the tampering detection information generating unit  2031  to repeat the process that embeds the electronic watermark information. Also, when the number of embedding attempts is equal to or above a predetermined threshold, the electronic watermark embedding unit  2039  may inform the user via the display unit  2013 . 
     Note that when time information is used to verify not only whether information has been tampered with but also whether the power management apparatus  11  has been taken over, such time information may be incorporated as part of the electronic watermark information as described above or such time information may be embedded in the appliance characterizing information separately to the electronic watermark information. 
     This completes the description of one example of the functions of the control-compliant appliance  125  according to the present embodiment. The various component elements described above may be configured using general-purpose parts and circuits or may be configured using hardware that is dedicated to the functions of the respective component elements. Alternatively, the functions of the respective component elements may all be carried out by a CPU or the like. Accordingly, it is possible to change the configuration in use as appropriate in accordance with the prevailing technical level when implementing the present embodiment. 
     For example, in  FIG. 26 , a case is shown where the battery  2005  is integrally formed with the control-compliant appliance  125 , but the battery may also be separately formed from the control-compliant appliance  125 . 
     Also, in addition to the processing units shown in  FIG. 26 , the control-compliant appliance  125  may further include a communication function such as a wide area communication unit. 
     Note that a computer program for realizing the functions of the control-compliant appliance according to the above embodiment may be created and installed in a personal computer or the like. It is also possible to provide a computer-readable recording medium on which such a computer program is stored. As examples, the recording medium may be a magnetic disk, an optical disc, a magneto-optical disc, or a flash memory. The computer program mentioned above may also be distributed via a network, for example, without using a recording medium. 
     (1-9) Configuration of Power Storage Apparatus 
     Next, the configuration of the power storage apparatus  128  according to the present embodiment will be described in detail with reference to  FIG. 30 .  FIG. 30  is a block diagram useful in explaining the configuration of the power storage apparatus according to the present embodiment. 
     As illustrated in  FIG. 30 , the power storage apparatus  128  mainly includes a control unit  2501 , a sensor  2503 , a cell  2505 , a local communication unit  2507 , a display unit  2509 , a storage unit  2511 , and the like. 
     The control unit  2501  is realized by a CPU, a ROM, a RAM, and the like, for example. The control unit  2501  is a processing unit that carries out execution control over processing units provided in the control-compliant appliance  125 . The control unit  2501  also transmits primary information and the like described earlier relating to the control-compliant appliance  125  to the power management apparatus  11 . Furthermore, if a problem such as breakdown occurs in the cell  2505  described later, the control unit  2501  carries out reconfiguring of cells (rearrangement of the cell configuration). Note that the configuration of the control unit  2501  will be described in detail later. 
     The sensor  2503  is composed of a current sensor or voltage sensor that monitors the state of the cell  2505  or a sensor capable of acquiring various physical data, such as a temperature sensor, humidity sensor, barometer, or the like that monitors the peripheral environment at the setup location of the power storage apparatus  128 . Based on control by the control unit  2501 , the sensor  2503  measures various physical data at specified time intervals or at arbitrary timing and outputs the obtained physical data to the control unit  2501  as sensor information. 
     The cell  2505  is a power storage device provided in the power storage apparatus  128 , is composed of one or a plurality of cells, and supplies power to the power storage apparatus  128  and apparatuses provided outside the power storage apparatus  128 . Power is supplied to the cell  2505  by external power or the power generating apparatuses  129 ,  130  present in the system  1  and is stored in the cell  2505 . The cell  2505  is controlled by the control unit  2501  and outputs various physical data to the control unit  2501  as cell information at specified time intervals or at arbitrary timing. 
     The local communication unit  2507  is realized by a CPU, a ROM, a RAM, and a communication apparatus or the like, for example. The local communication unit  2009  is communication means for communicating via a communication network constructed inside the local power management system  1 . The local communication unit  2507  is capable of communicating with the power management apparatus  11  according to the present embodiment via the communication network constructed inside the local power management system  1 . 
     The display unit  2509  is realized by a CPU, a ROM, a RAM, and an output apparatus or the like, for example. The display unit  2509  is a display device for displaying information relating to power consumption by the power storage apparatus  128 , user information, billing information, other information relating to power management, information relating to power management outside the local power management system  1 , information relating to power trading, and the like. Note that as examples, an LCD, an ELD, or the like is used as the display device. 
     The storage unit  2511  is one example of a storage apparatus provided in the power storage apparatus  128 . The storage unit  2511  stores identification information that is unique to the power storage apparatus  128 , information relating to various keys held by the power storage apparatus  128 , various digital signatures and/or certificates held by the power storage apparatus  128 , and the like. Various history information may also be recorded in the storage unit  2511 . In addition, various parameters and intermediate progress of processing that should be stored when the power storage apparatus  128  according to the present embodiment carries out processing or various databases or the like are recorded as appropriate in the storage unit  2511 . The various processing units of the power storage apparatus  128  are also capable of freely reading from and writing into the storage unit  2511 . 
     Configuration of Control Unit—Part 1 
     This completes the description of the overall configuration of a power storage apparatus  128  according to the present embodiment. The configuration of the control unit  2501  of a power storage apparatus  128  will now be described in detail with reference to  FIG. 31 . 
     As illustrated in  FIG. 31 , the control unit  2501  of a power storage apparatus  128  includes an authentication processing unit  2521 , a sensor control unit  2523 , a sensor information output unit  2525 , a cell control unit  2527 , and a cell information output unit  2529 . 
     The authentication processing unit  2521  is realized by a CPU, a ROM, a RAM, and the like, for example. The authentication processing unit  2521  carries out an authentication process together with the power management apparatus  11  based on a specified protocol and also carries out processing that registers a power storage apparatus  128  in the power management apparatus  11 . When carrying out processing with the power management apparatus  11 , the authentication processing unit  2521  is capable of using the various keys stored in the storage unit  2515  or the like, digital signatures or certificates provided by the manufacturer when the power storage apparatus  128  was manufactured, and various parameters and the like. The authentication process implemented by the authentication processing unit  2521  is not limited to any specified process and it is possible to use any arbitrary process in accordance with the content and configuration of the system  1 . 
     The sensor control unit  2523  is realized by a CPU, a ROM, a RAM, and the like, for example. The sensor control unit  2523  is a processing unit that controls the sensor  2503  provided in the power storage apparatus  128 . The sensor control unit  2523  carries out control over the sensor  2503  according to a specified method, acquires physical data measured by the sensor  2503  at specified time intervals or at arbitrary timing and outputs the physical data to the sensor information output unit  2525 , described later. 
     The sensor information output unit  2525  is realized by a CPU, a ROM, a RAM, and the like, for example. The sensor information output unit  2525  outputs sensor information outputted from the sensor control unit  2523  via the local communication unit  2509  to the power management apparatus  11 . The sensor information output unit  2525  may also implement preprocessing, such as a noise reduction process and a digitizing process, when outputting the sensor information. The sensor information output unit  2525  may use the information acquired from the sensor control unit  2523  to generate various types of secondary information and output such information as sensor information. 
     The cell control unit  2527  is realized by a CPU, a ROM, a RAM, and the like, for example. The cell control unit  2527  is a processing unit that controls the cell  2505  provided in the power storage apparatus  128 . The cell control unit  2527  uses the power stored in the cell  2505  to cause the power storage apparatus  128  to function and depending on the state, supplies the power stored in the cell  2505  to outside the power storage apparatus  128 . The cell control unit  2527  carries out control over the cell  2505  according to a specified method, acquires physical data measured by the cell  2505  at specified time intervals or at arbitrary timing and outputs the physical data to the cell information output unit  2529 , described later. 
     The cell information output unit  2529  is realized by a CPU, a ROM, a RAM, and the like, for example. The cell information output unit  2529  outputs cell information outputted from the cell control unit  2527  via the local communication unit  2509  to the power management apparatus  11 . The cell information output unit  2529  may also implement preprocessing, such as a noise reduction process and a digitizing process, when outputting the cell information. The cell information output unit  2529  may use the information acquired from the cell control unit  2527  to generate various types of secondary information and output such information as cell information. 
     Configuration of Control Unit—Part 2 
     The control unit  2501  of a power storage apparatus  128  may have the configuration described below instead of the configuration shown in  FIG. 31 . Another configuration of the control unit  2501  provided in a power storage apparatus  128  will now be described in detail with reference to  FIG. 32 . 
     As illustrated in  FIG. 32 , the control unit  2501  of a power storage apparatus  128  may include the authentication processing unit  2521 , the sensor control unit  2523 , the cell control unit  2527 , and a tampering detection information generating unit  2531 . 
     Since the authentication processing unit  2521  shown in  FIG. 32  has the same configuration as the authentication processing unit  2521  shown in  FIG. 31  and achieves the same effect, detailed description thereof is omitted. Similarly, aside from outputting the sensor control information and the cell information to the tampering detection information generating unit  2531 , the sensor control unit  2523  and the cell control unit  2527  shown in  FIG. 32  have the same configuration and achieve the same effects as the corresponding processing units shown in  FIG. 31 . Accordingly, detailed description thereof is omitted. 
     The tampering detection information generating unit  2531  is realized by a CPU, a ROM, a RAM, and the like, for example. The tampering detection information generating unit  2531  generates tampering detection information for use in detecting whether information has been tampered with based on the sensor information outputted from the sensor control unit  2523  and the cell information outputted from the cell control unit  2527 . The tampering detection information generating unit  2531  transmits the generated tampering detection information via the local communication unit  2509  to the power management apparatus  11 . The power management apparatus  11  may also transfer the tampering detection information generated by the tampering detection information generating unit  2531  to various servers, such as the analysis server  34 , provided outside the local power management system  1 . 
     Configuration of Tampering Detection Information Generating Unit 
     The detailed configuration of the tampering detection information generating unit  2031  will now be described with reference to  FIG. 33 .  FIG. 33  is a block diagram useful in explaining the configuration of the tampering detection information generating unit. 
     As illustrated in  FIG. 33 , the tampering detection information generating unit  2531  further includes an appliance characterizing information generating unit  2533 , an electronic watermark generating unit  2535 , an embedded position deciding unit  2537 , and an electronic watermark embedding unit  2539 . 
     Aside from generating the appliance characterizing information based on the sensor information outputted from the sensor control unit  2523  and the cell information outputted from the cell control unit  2527 , the appliance characterizing information generating unit  2533  has the same function and achieve the same effects as the appliance characterizing information generating unit  2033  shown in  FIG. 29 . Accordingly, detailed description thereof is omitted. 
     Furthermore, the electronic watermark generating unit  2535 , the embedded position deciding unit  2537  and the electronic watermark embedding unit  2539  have the same function and achieve the same effects as the corresponding processing units shown in  FIG. 29 . Accordingly, detailed description thereof is omitted. 
     This completes the description of one example of the functions of the power storage apparatus  128  according to the present embodiment. The various component elements described above may be configured using general-purpose parts and circuits or may be configured using hardware that is dedicated to the functions of the respective component elements. Alternatively, the functions of the respective component elements may all be carried out by a CPU or the like. Accordingly, it is possible to change the configuration in use as appropriate in accordance with the prevailing technical level when implementing the present embodiment. 
     For example, in addition to the processing units shown in  FIG. 30 , the power storage apparatus  128  may further include a communication function such as a wide area communication unit. 
     Note that a computer program for realizing the functions of the power storage apparatus according to the above embodiment may be created and installed in a personal computer or the like having the power storage apparatus. It is also possible to provide a computer-readable recording medium on which such a computer program is stored. As examples, the recording medium may be a magnetic disk, an optical disc, a magneto-optical disc, or a flash memory. The computer program mentioned above may also be distributed via a network, for example, without using a recording medium. 
     (1-10) Specific Examples of Method of Embedding and Method of Verifying Electronic Watermark Information 
     Specific examples of a method of embedding and a method of verifying the electronic watermark information will now be described in detail. 
     In the intelligent, networked, and digitized local power management system  1 , the power management apparatus  11  communicates with the various appliances and batteries about power usage by the respective appliances in the system so as to optimize power usage in the entire system. By doing so, the power management apparatus  11  monitors the sensor information from the respective appliances/batteries and states such as a date/time, power price, temperature, and whether the user is at home or out, and carries out control such as setting operation modes and maximum currents of respective appliances in accordance with such states. It also becomes possible to benefit from a variety of services such as control from outside the home via the power management apparatus  11 , to enact high security measures supported by a security check server, and optimization. 
     When doing so, since it becomes possible to access to the appliances and batteries from outside, there are increased security threats such as abnormal operation commands sent to appliances or batteries, attacks to a household power management apparatus or appliances or batteries launched from another power management apparatus, DoS attacks, and information leaks. Conceivable countermeasures to such threats include traffic management by the power management apparatus  11 , antivirus measures, and installing a firewall. To deal with unknown attacks, it is assumed that sensor information and execution command information for appliances or batteries are sent to a security check server such as the analysis server  34  and a physical simulation or learning theory is used to estimate the extent of danger and/or detect illegal usage. 
     However, since such countermeasures have a premise that the power management apparatus is operating normally, when the control function of the power management apparatus  11  has been compromised by an external attacker, such defenses will be ineffective. Also, since the appliances and batteries will probably have comparatively weak defenses due to the costs of manufacturing and management, in a state where the control function of the power management apparatus  11  has been compromised, the appliances and batteries that can be realistically imagined will be defenseless. In addition, although an attack where an illegal power management apparatus acts as a legitimate power management apparatus, tampers with physical data, and transmits such data to a security check server would be conceivable, since it is difficult for a service to distinguish between an illegal power management apparatus and a valid power management apparatus, it would be difficult to detect such attack. Since an attack on an appliance or battery has a higher risk of causing major damage compared to a conventional attack on a computer, it is necessary to provide not only the power management apparatus but also the appliances and batteries with a security function of a certain level. 
     For this reason, in the present embodiment, as described earlier, it is possible to insert an electronic watermark for preventing illegal tampering into the physical data obtained from sensors and the like of appliances and batteries. By using this method, it is possible to detect attacks even when the physical data has been tampered with by an attacker on a communication path. Also, even when the control function of a power management apparatus has been compromised, by regularly transmitting electronic watermark information that includes time information to a security check server, it is possible to detect through cooperation with services that the control function has been compromised. In addition, by using the electronic watermark information, it is unnecessary to transmit authentication information, such as a MAC, separately to the physical data, which makes it possible to use a power management apparatus that is capable of only receiving physical data. 
     The method of embedding and the method of verifying electronic watermark information will now be described more specifically by giving an example. Note that in the following explanation, it is assumed that the electronic watermark information is embedded into physical data (appliance characterizing information) obtained at a certain time. The physical data is time-series data composed of n data, and the value of the physical data at a time k (where 0≦k≦n−1) is expressed as X k . The physical data values at each time are subjected to discretization after being acquired from a sensor or the like and are set as r bit data. The data size of the electronic watermark information is set at m bits. 
     Method of Embedding and Method of Verifying Electronic Watermark Information Using Shared Information 
     A method of embedding and method of verifying electronic watermark information that uses shared information will now be described in detail by giving specific examples. 
     Specific Example 1 
     First, a method of embedding electronic watermark information carried out by the control-compliant appliance  125  or the like will be described. 
     First, the embedded position deciding unit  2037  of the tampering detection information generating unit  2031  uses a specified signal processing circuit or the like to select p data with large values out of the appliance characterizing information that is physical data or the like. After this, the electronic watermark embedding unit  2039  uses a specified embedding process circuit or the like to successively insert the electronic watermark information generated based on the shared information into a q(k) bit part counting from the least significant bit (LSB) of the selected p appliance characterizing information in time series order. Here, q(k) is a value that fulfills Condition a given below. 
     
       
         
           
             
               
                 
                   
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     In some cases, values of the selected p appliance characterizing information after the electronic watermark information has been embedded will be equal to or lower than values from the p+1 th  data onwards. In such a case, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  corrects the data aside from the embedded position of the electronic watermark information so that the values from the p+1 th  value onwards are below a lowest value of the appliance characterizing information after the embedding of the p electronic watermark information. The tampering detection information generating unit  2031  updates the electronic watermark information based on the values after correction and repeats the embedding process until the condition is satisfied. 
     Next, a method of verifying the electronic watermark information carried out by an information tampering detecting unit of the power management apparatus  11  or of a security check server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit uses a specified signal processing circuit or the like to specify p positions of data with large values out of the appliance characterizing information that is physical data or the like. Next, the electronic watermark extracting unit uses position information expressing the specified data position and a specified embedded extracting circuit or the like to successively extract values of q(k) bits counting from the LSB of the selected p appliance characterizing information in a time series. After this, an electronic watermark verification unit generates electronic watermark information based on shared information such as key information stored in a storage unit or the like and compares the generated information with the electronic watermark information extracted by the electronic watermark extracting unit. 
     Specific Example 2 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  will be described. 
     First, the embedded position deciding unit  2037  of the tampering detection information generating unit  2031  uses a specified signal processing circuit or the like to carry out a discrete Fourier transform expressed by Equation 101 below or a discrete cosine transform expressed by Equation 102 below to convert the appliance characterizing information (physical data) (X 0 , X 1 , . . . , X n−1 ) in a time domain to a data string (Y 0 , Y 1 , . . . , Y n−1 ) in a frequency domain. 
     
       
         
           
             
               
                 
                   
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     After this, the embedded position deciding unit  2037  selects p high frequency components (i.e., components where j is large in Equations 101 and 102) in order from the high frequencies. Next, the electronic watermark embedding unit  2039  uses a specified embedding processing circuit or the like to successively insert the electronic watermark information generated based on the shared information into a q(k) bit part counting from the least significant bit LSB of the selected p frequency domain data. Here, “q(k)” is a value that satisfies Condition a given above. 
     Here, as the method of embedding when a discrete Fourier transform is used, it is possible to use any arbitrary method, such as assigning uniformly to both real numbers and complex numbers or assigning with priority to large values. 
     Next, the electronic watermark embedding unit  2039  uses a specified signal processing circuit or the like to subject data in a frequency domain after the embedding of the electronic watermark information to an inverse discrete Fourier transform expressed by Equation 103 or to an inverse discrete cosine transform expressed by Equation 104 to restore the data to a data string in a time domain. 
     
       
         
           
             
               
                 
                   
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     Next, a method of verifying the electronic watermark information implemented by the information tampering detecting unit of either the power management apparatus  11  or a security check server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit first uses a specified signal processing circuit or the like to carry out the discrete Fourier transform expressed by Equation 101 above or the discrete cosine transform expressed by Equation 102 above to convert the appliance characterizing information (physical data) (X 0 , X 1 , . . . , X n−1 ) in a time domain to a data string (Y 0 , Y 1 , . . . , Y n−1 ) in a frequency domain. Next, the embedded position specifying unit selects p high frequency components (i.e., components where j is large in Equations 101 and 102) in order from the high frequencies. By doing so, it is possible to specify the position at which the electronic watermark information was embedded. After this, the electronic watermark extracting unit uses the position information showing the position of the specified data and successively extracts q(k) bit values counting from the least significant bit LSB of the selected p appliance characterizing information using a predetermined embedded extracting circuit or the like. An electronic watermark verifying unit then generates electronic watermark information based on shared information such as key information stored in a storage unit or the like, and compares the generated electronic watermark information with the electronic watermark information extracted by the electronic watermark extracting unit. 
     Specific Example 3 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  or the like will be described. 
     First, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  generates difference data S k =X k −X k−1  (1≦k≦n−1) based on the appliance characterizing information X k . Next, the embedded position deciding unit  2037  selects a p−1 consecutive data string S k (t≦k≦t+p−2, 1≦t≦n−p+1) so that the sum of p−1 consecutive difference data is below a specified threshold σ and the selected p−1 data have the highest sum of squares out of a consecutive data string that satisfies such condition. 
     After this, the electronic watermark embedding unit  2039  uses a specified embedding processing circuit or the like to successively insert the electronic watermark information generated based on the shared information into a q(k) bit part counting from the least significant bit LSB of the selected p appliance characterizing information X k (t−1≦k≦t+p−2) in time series order. Here, “q(k)” is a value that satisfies Condition a given above. 
     Regarding the consecutive difference data of the p selected appliance characterizing information after embedding of the electronic watermark information, there may be cases where it is no longer true that the sum is below the threshold a and/or the sum of squares is the highest out of a consecutive data string that satisfies such condition. In such a case, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  corrects the data aside from the embedded position of the electronic watermark information so that the conditions given above are true. The tampering detection information generating unit  2031  updates the electronic watermark information based on the values after correction and repeats the embedding process until the conditions above are true. 
     Next, a method of verifying the electronic watermark information implemented by the power management apparatus  11  and an information tampering detecting unit of a security check server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit first generates difference data S k =X k −X k−1  (1≦k≦n−1) for the appliance characterizing information X k . Next, the embedded position specifying unit selects a p−1 consecutive data string S k  (t≦k≦t+p−2, 1≦t≦n−p+1) where the sum of the p−1 consecutive difference data is below a predetermined threshold σ and a sum of squares is highest out of a consecutive data string that satisfies such condition. By doing so, it is possible to specify the position where the electronic watermark information was embedded. 
     After this, an electronic watermark extracting unit uses position information expressing the position of the specified data and a specified embedded extracting circuit or the like to successively extract values of a q(k) bit part counting from the LSB of the selected p appliance characterizing information (t−1≦k≦t+p−2) in time series order. Next, the electronic watermark verifying unit generates electronic watermark information based on shared information such as key information stored in a storage unit or the like and compares the generated electronic watermark information with the electronic watermark information extracted by the electronic watermark extracting unit. 
     Method of Embedding and Method of Verifying Electronic Watermark Information using Shared Information and Time Information 
     Specific examples of a method of embedding and method of verifying electronic watermark information that uses shared information have been described above. Next, a method of embedding and a method of verifying electronic watermark information that uses shared information and time information will be described by giving specific examples. 
     Note that since electronic watermark information that uses shared information and time information can also be used to detect whether the power management apparatus  11  has been taken over, the verification of such information is normally carried out by a security check server such as the analysis server  34 . 
     Note that when verifying electronic watermark information that uses time information, the security check server such as the analysis server  34  changes the method of verifying in accordance with how the time information is embedded. That is, if the time information was embedded together with the electronic watermark information, the embedded time information is extracted and used in a data generation process during verification. If the time information is not embedded, the electronic watermark information is generated using time information decided in advance or one or a plurality of time information selected based on an estimated acquisition time for the appliance characterizing information. 
     Specific Example 1 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  or the like will be described. 
     The electronic watermark generating unit  2035  of the tampering detection information generating unit  2031  uses a specified circuit or the like to generate m bit electronic watermark information for each appliance characterizing information based on an r−m (1≦m≦r−1) bit string counting from a most significant bit (MSB) of n appliance characterizing information (physical data), shared information such as key information, time information, and in some cases other information. 
     After this, the embedded position deciding unit  2037  uses a specified embedding circuit or the like to embed the electronic watermark information generated for each appliance characterizing information in an m bit part starting from the LSB of the appliance characterizing information. In this case, the data size of the entire electronic watermark information is nm bits. 
     Next, the method of verifying electronic watermark information implemented by an information tampering detecting unit of a security check server such as the analysis server  34  will be described. 
     First, an electronic watermark extracting unit of the information tampering detecting unit uses a specified embedded extracting circuit to extract m bits of data counting from the LSB of each of n appliance characterizing information as the electronic watermark information. Next, the electronic watermark verifying unit generates m bit electronic watermark information for each appliance characterizing information based on an r−m (1≦m≦r−1) bit string counting from the MSB of the n appliance characterizing information, shared information such as key information, time information, and data used by the embedding side. After this, the electronic watermark verifying unit generates electronic watermark information based on shared information such as key information stored in a storage unit or the like and compares the generated electronic watermark information with the electronic watermark information extracted by the electronic watermark extracting unit. 
     Note that although data in a time domain has been described in the above explanation, it is also possible to use the same equations on data on a frequency domain produced by converting appliance characterizing information such as physical data via a discrete Fourier transform or a discrete cosine transform. 
     Specific Example 2 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  or the like will be described. 
     The embedded position deciding unit  2037  of the tampering detection information generating unit  2031  uses a specified signal processing circuit or the like to select p data with large values out of the appliance characterizing information that is physical data or the like. 
     After this, the electronic watermark generating unit  2035  generates m bit electronic watermark information based on every bit (nr−m bits) aside from q(k) bits counting from the LSB of the selected p appliance characterizing information, shared information such as key information, time information, and in some cases other information. Here, “q(k)” is a value that satisfies Condition a given above. 
     Next, the electronic watermark embedding unit  2039  uses a specified embedding processing circuit or the like to successively insert the generated electronic watermark information into a q(k) bit part counting from the LSB of the selected p appliance characterizing information in time series order. 
     In some cases, values of the selected p appliance characterizing information after the electronic watermark information has been embedded will be equal to or lower than values from the p+1th data onwards. In such a case, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  corrects the data aside from the embedded position of the electronic watermark information so that the values from the p+1th value onwards are below a lowest value of the appliance characterizing information after the embedding of the p electronic watermark information. The tampering detection information generating unit  2031  updates the electronic watermark information based on the values after correction and repeats the embedding process until the condition is satisfied. 
     Next, the method of verifying electronic watermark information implemented by an information tampering detecting unit of a security check server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit uses a specified signal processing circuit or the like to specify p positions of data with large values out of the appliance characterizing information that is physical data or the like. Next, the electronic watermark extracting unit uses position information expressing the specified data position and a specified embedded extracting circuit or the like to successively extract values of q(k) bits counting from the LSB of the selected p appliance characterizing information in a time series. 
     Next, the electronic watermark verifying unit generates m bit electronic watermark information based on every bit (nr−m bits) of the portion where the electronic watermark information is not embedded, shared information such as key information, time information, and data used by the embedding side. Then, the electronic watermark verifying unit compares the electronic watermark information extracted by the electronic watermark extracting unit and the electronic watermark information that has been generated. 
     Specific Example 3 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  or the like will be described. 
     First, the embedded position deciding unit  2037  of the tampering detection information generating unit  2031  uses a specified signal processing circuit or the like to carry out a discrete Fourier transform expressed by Equation 101 above or a discrete cosine transform expressed by Equation 102 above to convert the appliance characterizing information (physical data) (X 0 , X 1 , . . . , X n−1 ) in a time domain to a data string (Y 0 , Y 1 , . . . , Y n−1 ) in a frequency domain. 
     After this, the embedded position deciding unit  2037  selects p high frequency components (i.e., components where j is large in Equations 101 and 102) in order from the high frequencies. 
     After this, the electronic watermark generating unit  2035  generates m bit electronic watermark information based on every bit (nr−m bits) aside from q(k) bits counting from the LSB of the selected p appliance characterizing information, shared information such as key information, time information, and in some cases other information. Here, “q(k)” is a value that satisfies Condition a given above. 
     Next, the electronic watermark embedding unit  2039  uses a specified embedding processing circuit or the like to successively insert the electronic watermark information generated based on the shared information into a q(k) bit part counting from the least significant bit LSB of the selected p frequency domain data. 
     Here, as the method of embedding when a discrete Fourier transform is used, it is possible to use any arbitrary method, such as assigning uniformly to both real numbers and complex numbers or assigning with priority to large values. 
     Next, the electronic watermark embedding unit  2039  uses a specified signal processing circuit or the like to subject data in a frequency domain after the embedding of the electronic watermark information to an inverse discrete Fourier transform expressed by Equation 103 or to an inverse discrete cosine transform expressed by Equation 104 to restore the data to a data string in a time domain. 
     Next, the method of verifying electronic watermark information implemented by an information tampering detecting unit of a security server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit first uses a specified signal processing circuit or the like to carry out the discrete Fourier transform expressed by Equation 101 above or the discrete cosine transform expressed by Equation 102 above to convert the appliance characterizing information (physical data) (X 0 , X 1 , . . . , X n−1 ) in a time domain to a data string (Y 0 , Y 1 , . . . , Y n−1 ) in a frequency domain. Next, the embedded position specifying unit selects p high frequency components (i.e., components where j is large in Equations 101 and 102) in order from the high frequencies. By doing so, it is possible to specify the position at which the electronic watermark information was embedded. After this, the electronic watermark extracting unit uses the position information showing the position of the specified data and successively extracts q(k) bit values counting from the least significant bit LSB of the selected p appliance characterizing information using a predetermined embedded extracting circuit or the like. 
     Next, the electronic watermark verifying unit generates m bit electronic watermark information based on every bit (nr−m bits) of the portion where the electronic watermark information is not embedded, shared information such as key information, time information, and data used by the embedding side. Then, the electronic watermark verifying unit compares the electronic watermark information extracted by the electronic watermark extracting unit and the electronic watermark information that has been generated. 
     Specific Example 4 
     First, a method of embedding the electronic watermark information implemented by the control-compliant appliance  125  or the like will be described. 
     First, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  generates difference data Sk=Xk−Xk−1 (1≦k≦n−1) based on the appliance characterizing information Xk. Next, the embedded position deciding unit  2037  selects a p−1 consecutive data string Sk(t≦k≦t+p−2, 1≦t≦n−p+1) so that the sum of p−1 consecutive difference data is below a specified threshold σ and the selected p−1 data have the highest sum of squares out of a consecutive data string that satisfies such condition. 
     After this, the electronic watermark generating unit  2035  generates m bit electronic watermark information based on every bit (nr−m bits) aside from q(k) bits counting from the LSB of the selected p appliance characterizing information, shared information such as key information, time information, and in some cases other information. Here, “q(k)” is a value that satisfies Condition a given above. 
     Next, the electronic watermark embedding unit  2039  uses a specified embedding processing circuit or the like to successively insert the electronic watermark information generated based on the shared information into a q(k) bit part counting from the least significant bit LSB of the selected p frequency domain data. 
     Regarding the consecutive difference data of the p selected appliance characterizing information after embedding of the electronic watermark information, there may be cases where it is no longer true that the sum is below the threshold a and/or the sum of squares is the highest out of a consecutive data string that satisfies such condition. In such a case, the appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  corrects the data aside from the embedded position of the electronic watermark information so that the conditions given above are true. The tampering detection information generating unit  2031  updates the electronic watermark information based on the values after correction and repeats the embedding process until the conditions above are true. 
     Next, a method of verifying the electronic watermark information implemented by the power management apparatus  11  and an information tampering detecting unit of a security check server such as the analysis server  34  will be described. 
     The embedded position specifying unit of the information tampering detecting unit first generates difference data Sk=Xk−Xk−1 (1≦k≦n−1) for the appliance characterizing information Xk. Next, the embedded position specifying unit selects a p−1 consecutive data string Sk (t≦k≦t+p−2, 1≦t≦n−p+1) where the sum of the p−1 consecutive difference data is below a predetermined threshold σ and a sum of squares is highest out of a consecutive data string that satisfies such condition. By doing so, it is possible to specify the position where the electronic watermark information was embedded. 
     After this, an electronic watermark extracting unit uses position information expressing the position of the specified data and a specified embedded extracting circuit or the like to successively extract values of a q(k) bit part counting from the LSB of the selected p appliance characterizing information (t−1≦k≦t+p−2) in time series order. 
     Next, the electronic watermark verifying unit generates m bit electronic watermark information based on every bit (nr−m bits) of the portion where the electronic watermark information is not embedded, shared information such as key information, time information, and data used by the embedding side. Then, the electronic watermark verifying unit compares the electronic watermark information extracted by the electronic watermark extracting unit and the electronic watermark information that has been generated. 
     A method of embedding and method of verifying electronic watermark information that use shared information and a method of embedding and method of verifying electronic watermark information that use shared information and time information have been described above while giving specific examples. By using such methods in the local power management system  1  according to the present embodiment, it is possible to detect developments such as whether information has been tampered with and whether a power management apparatus has been taken over. 
     Note that although a case where electronic watermark information is embedded into a region with large values has been specifically described in the above explanation, it is also possible to implement the same processing when the electronic watermark information is embedded in a region with high dispersion, a noise region, or the like. 
     (1-11) Method of Registering Power Management Apparatus 
     Next, a method of registering a power management apparatus implemented by the power management apparatus  11  will be described in order of the processing flow with reference to  FIGS. 34 and 35 .  FIG. 34  is a flowchart useful in explaining a method of registering a power management apparatus according to the present embodiment.  FIG. 35  is a flowchart useful in explaining a specific example of the method of registering a power management apparatus according to the present embodiment. 
     First the overall flow of the registering method of the power management apparatus  11  will be described with reference to  FIG. 34 . 
     The appliance management unit  1121  of the power management apparatus  11  first connects the power distribution apparatus  121  set up in the local power management system  1  (step S 1001 ). More specifically, the appliance management unit  1121  acquires a digital signature, a certificate, or the like, which was stored in the power distribution apparatus  121  when the power distribution apparatus  121  was manufactured, from the power distribution apparatus  121 , and recognizes the power distribution apparatus  121  automatically or via online recognition. The recognition process and registration process for the power distribution apparatus  121  are carried out according to the flow of a recognition process and registration process for a control-compliant appliance  125  or the like, described later. 
     After this, the appliance management unit  1121  displays a message asking the user for a content of information to be registered (registered information) on the display unit  116  provided in the power management apparatus  11 . The user operates the input unit  117  such as a touch panel or a keyboard provided in the power management apparatus  11  and inputs the content of registration information, such as that shown in  FIG. 20 , into the power management apparatus  11 . By doing so, the appliance management unit  1121  is capable of acquiring the registration information (step S 1003 ). 
     Next, the appliance management unit  1121  connects to the system management server  33  via the wide area communication unit  114  and authentication is carried out by the system management server  33  (step S 1005 ). Although it is possible to connect to the system management server  33  and carry out the authentication process using any arbitrary technique, as one example, public key encryption is used. 
     In the authentication process carried out by the system management server  33 , the system management server  33  informs the power management apparatus  11  of the authentication result. The appliance management unit  1121  refers to the received authentication result and judges whether the authentication succeeded (step S 1007 ). 
     When the authentication process by the system management server  33  failed, the appliance management unit  1121  determines an error content written in the authentication result (step S 1009 ). In a case (a) where the registration information is incomplete, the appliance management unit  1121  returns to step S 1003 , asks for the content of the incomplete registration information, and acquires the correct content. In a case (b) where the registration information is not incomplete but the authentication failed, the appliance management unit  1121  connects to the system management server  33  and the authentication process is carried out again. Also, in a case (c) where the authentication has failed for a specified number of consecutive iterations or more, the appliance management unit  1121  cancels the registration of the power management apparatus  11 . 
     Meanwhile, when the authentication process carried out by the system management server  33  has succeeded, the appliance management unit  1121  transmits the acquired registration information officially to the system management server  33  (step S 1011 ) and has the power management apparatus  11  registered in a database of the system management server  33 . 
     By carrying out processing according to the flow described above, the appliance management unit  1121  of the power management apparatus  11  is capable of registering the power management apparatus  11  itself in the system management server  33 . Note that when registration of the power management apparatus  11  has succeeded, the power management apparatus  11  regularly communicates with the system management server  33  and checks a current state. 
     Specific Example of Method of Registering Power Management Apparatus 
     Next, a specific example of a method of registering a power management apparatus will be described with reference to  FIG. 35 .  FIG. 35  shows an example of a method of registering a power management apparatus using public key encryption. 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has acquired openly available system parameters (public parameters) according to an arbitrary method. It is also assumed that identification information (ID) that is unique to the power management apparatus and a digital signature of identification information generated by the system management server  33  have been stored in the apparatus by the manufacturer, for example. In addition, it is assumed that the system management server  33  has a public key and a secret key that are unique to the system management server  33 . 
     When the user of the power management apparatus  11  has carried out an operation that starts the registration process for a power management apparatus, the key generating unit  1501  of the appliance management unit  1121  uses the public parameters to generate a key pair composed of a public key and a secret key (step S 1021 ). The key generating unit  1501  stores the generated key pair in the storage unit  113  or the like. 
     Next, the system registering unit  1503  encrypts the identification information of the power management apparatus, the digital signature of the identification information, and the generated public key using the public key of the system management server  33 . After this, the system registering unit  1503  transmits the generated cryptogram via the wide area communication unit  114  to the system management server  33  as a certificate issuance request (step S 1023 ). 
     On acquiring the certificate issuance request transmitted from the power management apparatus  11 , the system management server  33  first verifies the validity of the signature appended to the digital signature (step S 1025 ). More specifically, the system management server  33  uses the secret key that is concealed by the server to verify whether the digital signature appended to the identification information of the power management apparatus is valid. 
     If the verification has failed, the system management server  33  transmits an authentication result showing that the authentication failed to the power management apparatus  11 . Meanwhile, if the verification has succeeded, the system management server  33  adds the identification information of the power management apparatus  11  to a managed list in a database stored by the system management server  33  (step S 1027 ). 
     Next, the system management server  33  issues a public key certificate for the public key generated by the power management apparatus  11  (step S 1029 ) and transmits the generated public key certificate to the power management apparatus  11 . 
     On receiving the public key certificate transmitted from the system management server  33 , the system registering unit  1503  of the power management apparatus  11  verifies the public key certificate (step S 1031 ). If the verification of the public key certificate succeeds, the system registering unit  1503  transmits registration information to the system management server  33  (step S 1033 ). Note that such transmission of the registration information is carried out using encrypted communication. 
     On receiving the registration information transmitted from the power management apparatus  11 , the system management server  33  registers the received registration information in the managed list (step S 1035 ). By doing so, the process for registering the power management apparatus  11  carried out by the power management apparatus  11  and the system management server  33  is regarded as having succeeded (step S 1037 ). 
     A specific example of the process for registering the power management apparatus  11  has been described above. Note that the specific example of the registration method described above is merely one example, and the registration process according to the present embodiment is not limited to the above example. 
     (1-12) Method of Registering Control-Compliant Appliance 
     Next, the method of registering a control-compliant appliance  125  in the power management apparatus  11  will be described with reference to  FIGS. 36 to 38 .  FIG. 36  is a flowchart useful in explaining a method of registering a control-compliant appliance according to the present embodiment.  FIGS. 37 and 38  are flowcharts useful in explaining specific examples of the method of registering a control-compliant appliance according to the present embodiment. 
     Note that this method of registering will be described with the control-compliant appliance  125  as an example of a managed appliance managed by the power management apparatus  11 . The method of registering described below is carried out in the same way when registering the electric vehicle  124 , the power storage apparatus  128 , the first power generating apparatus  129 , and the second power generating apparatus  130  in the power management apparatus  11 . 
     First, the overall flow of the method of registering the control-compliant appliance  125  will be described with reference to  FIG. 36 . 
     When a control-compliant appliance  125  that is not registered is connected to the local power management system  1  managed by the power management apparatus  11 , the appliance management unit  1121  of the power management apparatus  11  detects that the control-compliant appliance  125  is connected to the system (step S 1041 ). More specifically, the power management apparatus  11  itself may detect that the control-compliant appliance  125  is connected or the power distribution apparatus  121  or a power point (the control-compliant outlet  123  or the outlet expansion apparatus  127 ) may detect that the control-compliant appliance  125  is connected and inform the power management apparatus  11 . As a result of this process, the power management apparatus  11  is able to grasp information (position information) relating to the outlet to which the control-compliant appliance  125  is connected. 
     Next, the appliance management unit  1121  implements an authentication process on the control-compliant appliance  125  that is newly connected. This authentication process may be carried out using any arbitrary technique, for example, public key encryption. By carrying out the authentication process, the appliance management unit  1121  acquires information such as that shown in  FIG. 20  from the control-compliant appliance  125 . 
     If the authentication of the control-compliant appliance  125  has failed, the appliance management unit  1121  ends the registration process for the control-compliant appliance  125 . Note that if the appliance management unit  1121  decides to attempt to authenticate the control-compliant appliance  125 , instead of the registration process being suddenly terminated, the processing may return to step S 1043  where the authentication process is repeated. 
     Meanwhile, when the authentication of the control-compliant appliance  125  has succeeded, the appliance management unit  1121  registers the control-compliant appliance  125  via the wide area communication unit  114  in the system management server  33  (step S 1047 ). Next, the appliance management unit  1121  issues a signature (digital signature), certificate, or the like to the control-compliant appliance  125  for which the authentication succeeded (step S 1049 ). After this, the appliance management unit  1121  registers the control-compliant appliance  125  in a management database stored in the storage unit  113  or the like (step S 1051 ). 
     Specific Example of Method of Registering Control-Compliant Appliance 
     Next, a specific example of a method of registering a control-compliant appliance will be described with reference to  FIGS. 37 and 38 .  FIGS. 37 and 38  show an example of method of registering a control-compliant appliance that uses public key encryption. 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has acquired openly available system parameters (public parameters) according to an arbitrary method. It is also assumed that identification information (ID) that is unique to the power management apparatus and a digital signature of identification information generated by the system management server  33  have been stored in the apparatus by the manufacturer, for example, and that a key pair composed of a public key and a secret key are also stored in the apparatus. It is further assumed that the system management server  33  stores a public key and a secret key that are unique to the system management server  33 . Finally, it is assumed that identification information (ID) that is unique to the control-compliant appliance  125  and a digital signature generated by the system management server  33  have been stored inside the control-compliant appliance  125  by the manufacturer, for example. 
     First, a specific example of a method of initially registering a control-compliant appliance will be described with reference to  FIG. 37 . 
     When a control-compliant appliance  125  is connected to the system  1  (more specifically, when the control-compliant appliance  125  is connected to a control-compliant outlet  123  or the like) (step S 1061 ), in the procedure described earlier, the managed appliance registering unit  1505  of the power management apparatus  11  detects that the control-compliant appliance  125  has been connected (step S 1063 ). 
     Next, the managed appliance registering unit  1505  acquires registration conditions such as a priority ranking shown in  FIG. 19  (step S 1065 ). More specifically, the managed appliance registering unit  1505  displays a message asking the user for the registration conditions on the display unit  116  provided in the power management apparatus  11 . The user operates the input unit  117 , such as a touch panel or a keyboard, provided in the power management apparatus  11  and inputs registration conditions such as those shown in  FIG. 19 , into the power management apparatus  11 . 
     After this, the managed appliance registering unit  1505  transmits a registration start signal via the local communication unit  111  to the control-compliant appliance  125  (step S 1067 ). 
     The authentication processing unit  2021  of the control-compliant appliance  125  that received the registration start signal transmits the identification information (ID) that is unique to the appliance and the digital signature generated by the system management server  33  to the power management apparatus  11  as an appliance registration request (step S 1069 ). 
     The managed appliance registering unit  1505  that received the appliance registration request uses the public key of the system management server  33  to verify the validity of the received digital signature (step S 1071 ). When the verification has failed, the managed appliance registering unit  1505  transmits an authentication result showing that the authentication failed to the control-compliant appliance  125 . Meanwhile, when the verification succeeded, the managed appliance registering unit  1505  requests the system management server  33  to register the identification information of the control-compliant appliance  125  and/or appliance information including the manufacturer name, model number, and the like of the control-compliant appliance  125  (step S 1073 ). 
     On receiving the registration request, the system management server  33  confirms whether the control-compliant appliance  125  included in the registration request is a legitimate appliance (that is, an appliance that has already been registered) (step S 1075 ). When the control-compliant appliance  125  is a legitimate appliance, the system management server  33  adds the received appliance information to a managed list in a database stored in the system management server  33  (step S 1077 ). 
     After this, the system management server  33  acquires information (appliance specification information) relating to the specification of the registered control-compliant appliance  125  from various databases stored by the system management server  33  itself or from a server belonging to the manufacturer or the like and transmits the acquired information to the power management apparatus  11  (step S 1079 ). 
     The managed appliance registering unit  1505  of the power management apparatus  11  then issues a signature (certificate) for the identification information (ID) of the control-compliant appliance using a key held by the managed appliance registering unit  1505  itself (step S 1081 ). After this, the managed appliance registering unit  1505  transmits the issued signature together with the identification information (ID) of the power management apparatus  11  to the control-compliant appliance  125  (step S 1083 ). 
     The authentication processing unit  2021  of the control-compliant appliance  125  stores the received signature and identification information (ID) of the power management apparatus  11  in a specified location such as the storage unit  2015  (step S 1085 ). The managed appliance registering unit  1505  of the power management apparatus  11  registers the appliance information of the control-compliant appliance  125  in a management database stored in the storage unit  113  or the like (step S 1087 ). By doing so, the process for initially registering a control-compliant appliance  125  is regarded as having succeeded (step S 1089 ). 
       FIG. 37  shows a process where the control-compliant appliance  125  is officially registered (initially registered) in the power management apparatus  11 . However, as one example, there may also be cases where a user wishes to register a control-compliant appliance  125 , which has already been registered in the power management apparatus  11  at the user&#39;s home, temporarily in a power management apparatus  11  provided at a friend&#39;s house. For this reason, the power management apparatus  11  according to the present embodiment is provided with a registration process for temporarily registering a control-compliant appliance  125  that has already been initially registered in another power management apparatus  11 . A process for temporarily registering a control-compliant appliance  125  will now be described with reference to  FIG. 38 . 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has acquired openly available system parameters (public parameters) according to an arbitrary method. It is also assumed that identification information (ID) that is unique to the power management apparatus and a digital signature of identification information generated by the system management server  33  have been stored in the apparatus by the manufacturer, for example, and that a key pair composed of a public key and a secret key is also stored in the apparatus. In addition, it is assumed that the system management server  33  has a public key and a secret key that are unique to the system management server  33 . Finally, it is assumed that identification information (ID) that is unique to the control-compliant appliance  125  and a digital signature generated by the system management server  33  have been stored inside the control-compliant appliance  125  by the manufacturer, for example, and that identification information (ID) and a signature of a registered power management apparatus have also been stored in the control-compliant appliance  125 . 
     When the control-compliant appliance  125  is connected to the system  1  (more specifically, when the control-compliant appliance  125  is connected to a control-compliant outlet  123  or the like) (step S 1091 ), in the procedure described earlier, the managed appliance registering unit  1505  of the power management apparatus  11  detects that the control-compliant appliance  125  has been connected (step S 1093 ). 
     Next, the managed appliance registering unit  1505  acquires registration conditions such as a priority ranking shown in  FIG. 19  (step S 1095 ). More specifically, the managed appliance registering unit  1505  displays a message asking the user for the registration conditions on the display unit  116  provided in the power management apparatus  11 . The user operates the input unit  117 , such as a touch panel or a keyboard, provided in the power management apparatus  11  and inputs registration conditions such as those shown in  FIG. 19 , into the power management apparatus  11 . 
     Next, the managed appliance registering unit  1505  transmits a registration start signal via the local communication unit  111  to the control-compliant appliance  125  (step S 1097 ). 
     The authentication processing unit  2021  of the control-compliant appliance  125  that received the registration start signal transmits the identification information (ID) of the registered power management apparatus  11 , the provided signature, and the identification information (ID) that is unique to the control-compliant appliance  125  to the power management apparatus  11  as an appliance registration request (step S 1099 ). 
     The managed appliance registering unit  1505  that received the appliance registration request checks the identification information (ID) that is unique to the control-compliant appliance  125  and is included in the appliance registration request (step S 1101 ). After this, based on the identification information (ID) that is unique to the control-compliant appliance  125 , the managed appliance registering unit  1505  requests the system management server  33  for the certificate of the control-compliant appliance  125  (step S 1103 ). 
     After confirming that the control-compliant appliance  125  that requested the certificate is not an appliance included in an expiry list (step S 1105 ), the system management server  33  transmits the requested certificate to the power management apparatus  11  (step S 1107 ). 
     The managed appliance registering unit  1505  of the power management apparatus  11  verifies the signature (a signature acquired from the registered power management apparatus  11 ) possessed by the control-compliant appliance  125  (step S 1109 ). When verification of the signature has succeeded, the managed appliance registering unit  1505  registers the control-compliant appliance  125  temporarily in the power management apparatus  11  (step S 1111 ). By doing so, the power management apparatus  11  is capable of temporarily registering the control-compliant appliance  125  that has already been registered in another power management apparatus  11 . 
     (1-13) Method of Registering Control-Compliant Outlet 
     Next, the method of registering a control-compliant outlet  123  in the power management apparatus  11  will be described with reference to  FIG. 39 .  FIG. 39  is a flowchart useful in explaining a method of registering a control-compliant outlet according to the present embodiment. 
     Note that although the following description uses the control-compliant outlet  123  as an example, this method of registering can be carried out in the same way for the outlet expansion apparatus  127 . 
     The appliance management unit  1121  of the power management apparatus  11  first connects to the power distribution apparatus  121  (step S 1121 ) and acquires information relating to outlets present in the system  1  from the power distribution apparatus  121  (step S 1123 ). The expression “information relating to outlets” refers to information such as an indication of control-compliant outlet or non-control-compliant outlet, identification information (ID) of a control-compliant outlet, a manufacturer name and model number, a specification such as amount of supplied power and supply limit, position information of an outlet inside the system, and the like. 
     Next, the managed appliance registering unit  1505  of the appliance management unit  1121  establishes a connection with a control-compliant outlet present in the system (step S 1125 ). After this, the managed appliance registering unit  1505  registers the control-compliant outlet with which a connection has been established in a management database stored in the storage unit  113  or the like (step S 1127 ). 
     Next, the managed appliance registering unit  1505  confirms the power supplying control method and appliance authentication means such as those shown in  FIG. 21 , and sets such information in the management database. By doing so, when a control-compliant appliance  125  or a non-control-compliant appliance  126  is connected to the control-compliant outlet  123 , the power management apparatus  11  is capable of carrying out an appropriate power supplying control and appliance authentication process. 
     Next, the managed appliance registering unit  1505  judges whether the process has been implemented for every outlet (control-compliant outlet) (step S 1131 ). When a control-compliant outlet for which the process has not been implemented is present, the managed appliance registering unit  1505  returns to step S 1125  and the processing continues. When the process has been implemented for every control-compliant outlet, the managed appliance registering unit  1505  ends the processing normally. 
     This completes the description of the processes for registering the respective apparatuses in the local power management system  1  according to the present embodiment. 
     (1-14) Billing Process for Temporarily Registered Control-Compliant Appliance 
     A billing process for a temporarily registered control-compliant appliance will now be described with reference to  FIGS. 40 and 41 .  FIG. 40  is a diagram useful in explaining a billing process for a temporarily registered control-compliant appliance.  FIG. 41  is a flowchart useful in explaining a billing process for a temporarily registered control-compliant appliance. 
     As described above, a state can be imagined where a control-compliant appliance  125  that has already been registered in a certain power management apparatus  11  is temporarily registered in another power management apparatus  11  that manages a different local power management system  1 . When doing so, a situation may occur where the temporarily registered control-compliant appliance  125  receives the supplying of power from such different local power management system  1  under the control of the other power management apparatus  11 . 
     This situation is shown in  FIG. 40 . As shown in  FIG. 40 , a control-compliant appliance # 1  that belongs to a local power management system # 1  is already registered in the power management apparatus # 1 . The control-compliant appliance # 1  has received, from the power management apparatus # 1 , the identification information (ID P1 ) of the power management apparatus # 1  and the digital signature (sig(ID P1 ) of the power management apparatus # 1  on the identification information of the control-compliant appliance # 1 . Here, a situation is imagined where the control-compliant appliance # 1  is temporarily registered in a local power management system # 2  (for example, a public power supplying station or the like) that is managed by a power management apparatus # 2  and the control-compliant appliance # 1  receives the supplying of power from the local power management system # 2 . Here, it is assumed that the system management server  33  has grasped the identification information (ID P1 ) of the power management apparatus # 1  and the identification information (ID P2 ) of the power management apparatus # 2 . 
     It is preferable for the fee for such power usage to be billed to the power management apparatus # 1  in which the control-compliant appliance# 1  is registered and for the power management apparatus # 1  to implement a specified billing process with the billing server  32 . This arrangement is only possible when the appliance stores a public key and a secret key, and when such information is not stored, the power management apparatus # 2  will end up supplying power to the control-compliant appliance # 1  free of charge. Note that even when a key pair composed of the public key and the secret key is stored, the supplying of power free of charge may be permitted depending on what settings have been made. 
     A potential problem in this situation is that when the power management apparatus # 1  is an illegal apparatus, even if power is supplied to the control-compliant appliance # 1  by the power management apparatus # 2 , the billing of the fee may be invalid. For this reason, in the present embodiment, before the supplying of power to the control-compliant appliance # 1  is permitted, the power management apparatus # 2  confirms the validity of the power management apparatus # 1  and that the control-compliant appliance # 1  is officially registered in the power management apparatus # 1 . Such confirmation operations should preferably also be carried out for safety even when the power management apparatus # 2  supplies power free of charge. That is, the power management apparatus # 2  uses the signature of the power management apparatus # 1  and/or certificates or the like to verify the relationship between the power management apparatus # 1  and the control-compliant appliance # 1  whenever power is supplied and also enquires to the system management server  33  to check the validity of the power management apparatus # 1  and the control-compliant appliance # 1 . 
     Also, in the present embodiment, regarding billing of a fee, as described below with reference to  FIG. 41 , it is possible to realize a safe billing process by incorporating the exchanging of the supplying of power and a power usage certificate that officially proves that power has been used. 
     The flow of a billing process for a control-compliant appliance that has been temporarily registered will now be described with reference to  FIG. 41 . Note that the following process is mainly carried out by the control unit  2001  of the control-compliant appliance  125  and the appliance management unit  1121  of the power management apparatus  11 . 
     First the control-compliant appliance # 1  requests the power management apparatus # 2  to carry out the authentication process (step S 1141 ). When requesting authentication, the control-compliant appliance # 1  transmits the identification information (ID P1 ) of the power management apparatus # 1 , the identification information (ID d1 ) of the control-compliant appliance # 1 , and digital signatures for ID P1  and ID d1  that are stored in the control-compliant appliance # 1  to the power management apparatus # 2 . 
     The power management apparatus # 2  checks whether the received identification information (ID d1 ) of the control-compliant appliance is present in a managed list managed by the power management apparatus # 2  itself. The power management apparatus # 2  also checks whether the identification information (ID P1 ) of the power management apparatus # 1  is present in a certificate list stored by the power management apparatus # 2 . By doing so, the power management apparatus # 2  checks the power management apparatus # 1  (step S 1143 ). 
     If the identification information of the power management apparatus # 1  is not present in the certificate list stored by the power management apparatus # 2 , the power management apparatus # 2  requests the system management server  33  for the certificate of the power management apparatus # 1  (step S 1145 ). In accordance with the request for the certificate, the power management apparatus # 1  may inform the system management server  33  of the identification information of the control-compliant appliance # 1 . 
     By checking whether the power management apparatus # 1  is not in an expiry list, the system management server  33  checks the validity of the power management apparatus # 1  (step S 1147 ). If the identification information of the power management apparatus # 1  is included in the expiry list, the system management server  33  informs the power management apparatus # 2  of this and the power management apparatus # 2  ends the processing in error. 
     Meanwhile, the power management apparatus # 2  requests the control-compliant appliance # 1  for a certificate issued by the power management apparatus # 1  or a digital signature generated by the power management apparatus # 1  (step S 1149 ). On receiving this request, the control-compliant appliance # 1  sends a digital signature (sig(ID P1 )) provided from the power management apparatus # 1  to the power management apparatus # 2  (step S 1151 ). 
     When the system management server  33  has confirmed the validity of the power management apparatus # 1 , the system management server  33  sends the certificate of the power management apparatus # 1  stored in the system management server  33  to the power management apparatus # 2  (step S 1153 ). 
     The power management apparatus # 2  verifies a digital signature and/or certificate transmitted from the control-compliant appliance # 1  (step S 1155 ), and when the verification succeeds, permits the supplying of power to the control-compliant appliance # 1 . At this time, the power management apparatus # 2  informs the control-compliant appliance # 1  of whether power is subject to a fee or is free of charge. If the power is free of charge, the following steps are not carried out. 
     Since the verification has succeeded, the power management apparatus # 2  supplies power to the control-compliant appliance # 1  for a specified time (step S 1157 ). 
     The control-compliant appliance # 1  that has received the supplying of power generates a message relating to power usage as evidence to prove that power has been consumed for a specified time, and transmits the message to the power management apparatus # 2  appended with a signature (step S 1159 ). The message relating to power usage to which the signature has been appended is a power usage certificate. Note that the processing in step S 1157  and step S 1159  should preferably be repeatedly carried out at fixed intervals until the power management apparatus # 2  stops the supplying of power or the control-compliant appliance # 1  is disconnected from the power network (the local power management system). 
     The power management apparatus # 2  transmits the power usage certificate acquired from the power management apparatus # 1  to the system management server  33  having added the identification information (ID P2 ) of the power management apparatus # 2  and the certificate of the appliance (step S 1161 ). 
     The system management server  33  verifies whether “the control-compliant appliance # 1  has purchased power from the power management apparatus # 2 ”. This verification is carried out by verifying the power usage certificate using the certificate of the appliance (step S 1163 ). 
     When verification of the power usage certificate succeeds, the system management server  33  requests the billing server  32  to carry out the billing process (step S 1165 ). After this, the billing server  32  carries out the billing process in accordance with the content of the request from the system management server  33  (step S 1167 ). 
     By carrying out such processing, it is possible to realize a safe billing process function that can be expanded to a public station. 
     Note that out of the control-compliant appliances and the like managed by the power management apparatus  11 , it would be conceivably possible for the electric vehicle  124  or the like that is equipped with a large-capacity battery to sell the power stored in the battery to another power network (local power management system). Such situation could also be handled using the procedure shown in  FIG. 41 . In such a case, the power management apparatus  11  receives power from the electric vehicle  124  or the like and the power management apparatus  11  issues a power usage certificate to the electric vehicle  124  or the like. Here, it is preferable for the power management apparatus  11  that has purchased the power to be fundamentally in charge of the sending of the power usage certificate to the system management server  33 . 
     It is also conceivable for a power management apparatus  11  that has received the supplying of power to do so illegally, for example, by not sending a power usage certificate to the system management server  33 . In this case, such illegal activity can be detected by having the power management apparatus  11  in which the electric vehicle  124  or the like is registered send a power usage certificate stored in the electric vehicle  124  or the like to the system management server  33 . 
     (1-15) Modification to Method of Registering Control-Compliant Appliance 
     Here, an example modification to the method of registering a control-compliant appliance described earlier will be described in detail with reference to  FIGS. 42 to 48 .  FIGS. 42 to 47  are diagrams useful in explaining a modification to the method of registering a control-compliant appliance, and  FIG. 48  is a flowchart useful in explaining a modification to the method of registering a control-compliant appliance. 
     As described earlier, in the local power management system  1 , authentication is carried out for appliances and batteries with aims such as preventing power from being supplied to illegal appliances and illegal batteries and preventing illegal appliances and illegal batteries from connecting to the system. The aim of the example modification to the method of registering a control-compliant appliance according to the present embodiment described below is to provide a method of registering that is capable of efficiently carrying out authentication of a control-compliant appliance or a power storage apparatus including a plurality of batteries. 
     In the following explanation, as illustrated in  FIG. 24 , a case where the power management apparatus  11  authenticates and registers eight control-compliant appliances  125  indicated as “A” to “H” is considered. 
     In the method described above, a one-to-one authentication process carried out between the power management apparatus  11  and one control-compliant appliance  125  is repeated a total of eight times for the control-compliant appliances  125 . In this case, when authenticating a single control-compliant appliance  125 , the following processes are carried out. That is, first the power management apparatus  11  transmits a challenge message including a random number to the control-compliant appliance  125 . Next, the control-compliant appliance  125  generates a response message by performing an action on the challenge message using a key stored by the control-compliant appliance  125 , and sends the response message in reply. After this, the power management apparatus  11  verifies whether the received response message is correct. 
     Here, authentication methods can be roughly classified into two types composed of (i) methods that use a secret key used in public key encryption as the key when performing the action to generate the response message from the challenge message so that the response message is a digital signature, and (ii) methods that use common key encryption using a key shared between the power management apparatus  11  and the control-compliant appliance  125 . 
     This example modification focuses on an authentication method that uses a digital signature as indicated by (i) above. This is because such authentication methods include methods that are capable of using techniques known as batch verification and aggregate signatures. 
     Here, the expression “batch verification” refers to a verification technique that is capable of carrying out verification on a plurality of digital signatures collectively in a single operation, with the verification algorithm outputting “verification successful” only when all of the digital signatures are correct. By using this technique, it is possible to increase computational efficiency compared to when verification is carried out separately for individual digital signatures. 
     Specific examples of batch verification processing are the methods disclosed in D. Naccache et al., “Can D. S. A be improved? Complexity trade-offs with the digital signature standard,” Proceedings of Eurocrypt 94, Lecture Notes in Computer Science Vol. 950, Springer-Verlag, 1994, and M. Bellare et al., “Fast Batch Verification for Modular Exponentiation and Digital Signatures,” Proceedings of Eurocrypt 98, Lecture Notes in Computer Science Vol. 1403, Springer-Verlag, 1998. In the present modification, by using batch verification processing, the computational efficiency can be improved. Such techniques include techniques that are capable of collectively verifying signatures generated by a plurality of signatories in response to respectively different messages. 
     The expression “aggregate signature” refers to a technique that is capable of aggregating a plurality of signatures into a single signature, and when a verification process is carried out on the aggregated signatures, the verification algorithm outputs “verification successful” only when all of the signatures are correct. Here, the plurality of signatures may be generated by a plurality of signatories in response to respectively different messages. 
     Specific examples of aggregate signatures are the methods disclosed in D. Boneh et al., “Aggregate and Verifiably Encrypted Signatures from Bilinear Maps,” Proceedings Eurocrypt 2003, Lecture Notes in Computer Science Vol. 2656, Springer-Verlag, 2003, and D. Boneh et al., “A Survey of Two Signature Aggregation Techniques,” CryptoBytes Vol. 6, No. 2, 2003. In this modification, by using an aggregate signature, the computational efficiency can be improved. 
     Here, as shown in  FIG. 42 , a case where the power management apparatus  11  authenticates eight control-compliant appliances  125  is considered. In a normal method where one-to-one authentication is repeated, a total of eight authentication processes are implemented, but by using a batch verification process or an aggregate signature, it is possible to improve the computational efficiency as shown in the lower part of  FIG. 42 . 
     Note that the authentication process described below is mainly carried out by the appliance management unit  1121  of the power management apparatus  11  and the control unit  2001  of the control-compliant appliance  125 . 
     First, the power management apparatus  11  transmits a challenge message C to the control-compliant appliances A to H (step S 1171 ). Since it is not necessary during such transmission to send individual messages to the respective control-compliant appliances, broadcasting may be used if the communication network is an environment that allows broadcasting. 
     The control-compliant appliances A to H respectively use secret keys for public key encryption that are held in the appliances on the challenge message C to generate response messages to the challenge message C and send the generated response messages in reply to the power management apparatus  11 . 
     For example, on receiving the challenge message C, the control-compliant appliance A uses the secret key stored by the control-compliant appliance A to generate the response message RA in reply to the challenge message C (step S 1173 ). After this, the control-compliant appliance A transmits the generated response message RA to the power management apparatus  11  (step S 1175 ). 
     Similarly, on receiving the challenge message C, the control-compliant appliance H uses the secret key stored by the control-compliant appliance H to generate the response message RH in reply to the challenge message C (step S 1177 ). Next, the control-compliant appliance H transmits the generated response message RH to the power management apparatus  11  (step S 1179 ). 
     More specifically, the response messages RA to RH are digital signatures of the respective control-compliant appliances A to H on the challenge message C. 
     During this time, the power management apparatus  11  waits for the response messages from the control-compliant appliances A to H for which the authentication process is being implemented. The power management apparatus  11  gathers response messages from the eight control-compliant appliances, collectively authenticates all of the response messages RA to RH (step S 1181 ), and verifies whether all of the response messages are correct. This verification may be carried out by a batch verification process or may be carried out by aggregating the eight response messages into a single digital signature using an aggregate signature technique and carrying out verification on the resulting digital signature. 
     Note that although the power management apparatus  11  is assumed to already know the public key of each control-compliant appliance to simplify the above explanation, the control-compliant appliances A to H may transmit their respective public key certificates to the power management apparatus  11  together with the response messages. 
     Here, a public key certificate is a digital signature of the certificate authority server  35  on identification information (ID) and/or public keys of appliances. This means that it is possible to efficiently carry out verification using a technique such as batch verification or an aggregate signature. 
     When the response messages from the respective control-compliant appliances sent in reply to the challenge message from the power management apparatus  11  have been gathered and the response messages are collectively verified, in many cases all of the response messages will be correct and the verification result will be “successful”. In such case, since the power management apparatus  11  has confirmed the validity of all of the control-compliant appliances A to H, processing may be carried out as normal. 
     However, in some cases “verification failed” is outputted during a collective verification process carried out on n appliances. This means that at least one abnormal appliance is present among the n control-compliant appliances. Accordingly, it is important for the power management apparatus  11  to specify the control-compliant appliances that are abnormal and carry out separate processing for such abnormal appliances, in addition to carrying out a new collective verification process on the appliances that are normal. 
     Appliances that are abnormal may be specified by repeatedly dividing the group of control-compliant appliances that was subjected to collective verification into smaller groups. Two specific methods of doing so are described below with reference to  FIGS. 43 and 44 . 
     A first strategy is a method that specifies a minimum of one appliance that is abnormal, with the number of iterations (computational load) necessary to do so being given as O(log 2n). 
     A second strategy is a method for specifying all of the abnormal appliances, with the number of iterations necessary to do so being given as O(n). 
     Methods based on the respective strategies will now be described in detail. 
     Strategy 1 is a method that selects one group (for example, a group with the smallest number of component elements) out of the groups for which the collective verification result is “failed” and repeatedly carries out collective verification until only one control-compliant appliance is included in a group.  FIG. 43  shows an example of this method. In  FIG. 43 , three control-compliant appliances C, E, and F out of the control-compliant appliances A to H are abnormal. 
     As step  1 , the power management apparatus  11  transmits a challenge message to all eight of the control-compliant appliances and carries out collective verification on the eight control-compliant appliances. If the verification result is “failed”, the power management apparatus  11  proceeds to step  2  where the single group composed of eight control-compliant appliances is divided into two groups. 
     In the example shown in  FIG. 43 , the power management apparatus  11  divides the group into a group composed of the control-compliant appliances A to D and a group composed of the control-compliant appliances E to H, and transmits a challenge message to the respective groups. After this, the power management apparatus  11  carries out collective verification on the obtained response messages in group units. In the example shown in  FIG. 43 , the result of the collective verification is “verification failed” for both groups. 
     Next, as step  3 , the power management apparatus  11  selects the next group to be divided out of the present groups (in  FIG. 43 , the group of the control-compliant appliances ABCD and the group of the control-compliant appliances EFGH) for which the verification result was “failed” (i.e., out of both groups). In the example shown in  FIG. 43 , the power management apparatus  11  selects the group composed of the control-compliant appliances ABCD and further divides the group. In the example shown in  FIG. 43 , the group composed of the control-compliant appliances ABCD is divided into two groups of two appliances in the form of a group composed of the control-compliant appliances AB and a group composed of the control-compliant appliances CD. 
     The power management apparatus  11  then transmits a challenge message to the two groups of two appliances and carries out collective verification on the received response messages. In the example shown in  FIG. 43 , since the verification result of the group composed of the control-compliant appliances AB is “succeeded”, it is confirmed that the control-compliant appliances A, B are both normal. Meanwhile, since the verification result of the group composed of the control-compliant appliances CD is “failed”, it is understood that at least one of the control-compliant appliances C, D is abnormal. 
     Next, as step  4 , the power management apparatus  11  divides the group composed of the control-compliant appliances CD into groups of single appliances and carries out an authentication process on each group. By doing so, the power management apparatus  11  can specify that the control-compliant appliance C is abnormal. 
     In the example shown in  FIG. 43 , it is possible to specify one control-compliant appliance that is abnormal out of eight control-compliant appliances in steps on four levels. In general terms, if the number of control-compliant appliances is n, a binary tree with n leaf nodes can be easily envisaged, but by dividing into groups so that the number of component elements is approximately halved, it is possible to complete the processing in log 2 (n+1) steps that is the height of the binary tree. Since the verification process is carried out on a maximum of two groups in one step, the number of iterations of the verification process is given as O(log 2 n). 
     Next, strategy 2 will be described. 
     Strategy 2 is a method for detecting all abnormal appliances.  FIG. 44  shows an example of this method. In  FIG. 44 , three control-compliant appliances C, E, and F out of the control-compliant appliances A to H are abnormal. 
     As step  1 , the power management apparatus  11  transmits a challenge message to all eight of the control-compliant appliances and carries out collective verification on the eight control-compliant appliances. If the verification result is “failed”, the power management apparatus  11  proceeds to step  2  where the single group composed of eight control-compliant appliances is divided into two groups. 
     In the example shown in  FIG. 44 , the power management apparatus  11  divides the group into a group composed of the control-compliant appliances A to D and a group composed of the control-compliant appliances E to H, and transmits a challenge message to the respective groups. After this, the power management apparatus  11  carries out collective verification on the obtained response messages in group units. In the example shown in  FIG. 44 , the result of the collective verification is “verification failed” for both groups. 
     In strategy 2, as step  3 , the authentication process is repeated on all of the groups for which the verification “failed” in the preceding step. In the example shown in  FIG. 44 , the group composed of the control-compliant appliances ABCD is divided into a group composed of the control-compliant appliances AB and a group composed of the control-compliant appliances CD. The power management apparatus  11  also divides the group composed of the control-compliant appliances EFGH into a group composed of the control-compliant appliances EF and a group composed of the control-compliant appliances GH. After this, the power management apparatus  11  implements a verification process separately on the resulting four groups. 
     In the example shown in  FIG. 44 , the verification result is “succeeded” for the group composed of the control-compliant appliances AB and the group composed of the control-compliant appliances GH, and is “failed” for the group composed of the control-compliant appliances CD and the group composed of the control-compliant appliances EF. 
     Next, in step  4 , the power management apparatus  11  divides the group composed of the control-compliant appliances CD for which verification failed into a group composed of the control-compliant appliance C and a group composed of the control-compliant appliance D. In the same way, the power management apparatus  11  divides the group composed of the control-compliant appliances EF for which verification failed into a group composed of the control-compliant appliance E and a group composed of the control-compliant appliance F. The power management apparatus  11  then carries out an authentication process individually on the new four groups. 
     As a result, as shown in  FIG. 44 , the authentication ends in “succeeded” for the control-compliant appliance D and in “failed” for the other three control-compliant appliances. By doing so, the power management apparatus  11  is capable of specifying all of the control-compliant appliances C, E, and F that are abnormal. 
     The number of steps in strategy 2 is four in the same way as in strategy 1, but in an I th  step, a verification process is carried out on 2I-1 groups. In this method, in some case, such as when abnormal appliances and normal appliances are alternately aligned, the verification process will be carried out on every appliance, so that the number of verification iterations is 2n. This means that the computational load for strategy 2 is O(n). 
     However, the power management apparatus  11  is a device that grasps the types of control-compliant appliance and the like are connected to the local power management system  1 . This is because such information is necessary to control which appliances are to be supplied with power. That is, when the user introduces an appliance into a local power management system  1  in the home, for example, a process that registers the appliance in the power management apparatus  11  is carried out. Accordingly, as described earlier, the power management apparatus  11  manages a list of the registered appliances. 
     Here, in the local power management system  1 , it is assumed that the eight appliances, control-compliant appliance A to control-compliant appliance H, have been registered in the power management apparatus  11 , but as a result of authentication, it has become known that the control-compliant appliance C is abnormal. 
     In this case, the power management apparatus  11  deletes the control-compliant appliance C from the managed list or marks the control-compliant appliance C as temporarily unusable. By doing so, the power management apparatus  11  is capable of excluding the control-compliant appliance C in advance from authentication during the next iteration of authentication, which enables a corresponding reduction to be made in the load of the authentication process. For example, if the seven control-compliant appliances aside from the control-compliant appliance C are normal, it is possible to confirm this in a single authentication carried out on the seven control-compliant appliances. 
     Also, if the power management apparatus  11  has been informed, via a user indication, that an appliance has been repaired and is back to normal, or if a “succeeded” result is obtained by the power management apparatus  11  regularly or irregularly attempting to authenticate the appliances that are abnormal, the power management apparatus  11  may correct the managed list managed by the power management apparatus  11  so that appliances that were previously excluded from the authentication are treated as normal. 
     Authentication of Batteries 
     In many cases, a plurality of battery cells are provided inside a battery casing. By combining such plurality of cells, it is possible for a battery to produce a variety of outputs. 
     For example,  FIG. 45  shows an example of a power storage apparatus  128  equipped with six 1V battery cells. As shown in  FIG. 45 , such cells A to F are capable of being combined so as to output various voltages. If arrangements where some of the cells are not used and/or where the power storage apparatus  128  is provided with not one but a plurality of pairs of output terminals are also considered, it is possible to achieve an even larger number of output variations. 
     If a battery includes failed cells and/or cells that have been illegally manufactured, there is an increased risk not only of the desired output not being achieved but also of accidents such as fire occurring during charging or the like. For this reason, it is important to carry out authentication on the individual battery cells to confirm that each cell (and moreover the battery itself) is normal. 
     Here, it would be conceivably possible for the power management apparatus  11  or a control unit of a battery to authenticate the individual cells. When doing so, as shown in  FIG. 46 , it would be conceivable to use six cells in combinations of three cells to obtain an output of 3V. Here, by normally repeating a process where the power management apparatus  11  or the control unit of a battery authenticates one cell, it is possible for the control unit of the battery to grasp the states of all of the cells in advance. The power management apparatus  11  is capable of acquiring the cell configuration of the battery from an external server or the like based on a model number or the like registered in the power management apparatus  11 . 
     In a case where a 3V voltage is desired, even with a low ampacity, it is possible to carry out authentication on the three cells A and B and C (or D and E and F) and use such cells as a battery. In such case, three verification processes are carried out. 
     However, by carrying out collective verification of ABC (or DEF) using a technique such as batch verification or an aggregate signature described earlier, it is possible to grasp whether it is possible to use the cells as a 3V battery via a single verification process, thereby improving the efficiency of the authentication process. In addition, if the verification “succeeded” is given for at least one of the group composed of ABC and the group composed of DEF, it is possible to easily grasp that the cells can be used as a battery. 
     In addition, when there is a group for which the authentication result is “failed”, by successively dividing the group using the methods described earlier, it is possible to specify the abnormal cells. 
     As shown in  FIG. 46 , when a voltage of 2V is desired, collective authentication may be carried out on the groups AB, CD, EF where two cells are connected in series. 
     In this way, by dividing the cells to be authenticated into groups in accordance with the combinations of the battery cells, it is possible to improve the efficiency of the authentication process. 
     It is assumed here that as shown in (the initial state in)  FIG. 47 , six battery cells are used to produce a voltage of 2V. Here, it is assumed that all of the six cells are normal in an initial state but an authentication result of “failed” is given when authentication is carried out at a given time. 
     The power management apparatus  11  and the control unit of the battery are capable of using strategy 2 described earlier to specify all of the cells that are abnormal. As a result, as shown in the center of  FIG. 47 , it is assumed here that cell D and cell E have been specified as abnormal. 
     In this case, the control unit of the battery or the power management apparatus  11  is capable of switching the wiring that connects the battery cells to reconfigure the cells as shown in the right on  FIG. 47 . By doing so, it is possible to use only normal cells to configure a combination that is capable of being used as a battery. If reconfiguring were not carried out, the normal cells C and F would be unavoidably wasted, but by carrying out reconfiguration, it is possible to use resources without waste. This reconfiguring of cells can be achieved by the control unit of the battery or the power management apparatus  11  accurately grasping the states of the respective cells and reconfiguring the connections between the cells in accordance with the authentication result. 
     The overall flow of batch authentication of control-compliant appliances described above is shown in  FIG. 48 . 
     First, the appliance management unit  1121  of the power management apparatus  11  generates a challenge message and broadcasts the challenge message to all of the control-compliant appliances  125  to be authenticated (step S 1191 ). By doing so, the control unit  2001  of each control-compliant appliance  125  generates a response message in reply to the challenge message and sends back the generated response message to the power management apparatus  11 . 
     In the power management apparatus  11 , the response messages transmitted from the control-compliant appliances  125  are awaited, and when a response message is transmitted from a control-compliant appliance  125 , the power management apparatus  11  acquires the transmitted response message (step S 1193 ). 
     Here, the appliance management unit  1121  of the power management apparatus  11  judges whether all of the response messages have been acquired (step S 1195 ). If some of the response messages have not been acquired, the appliance management unit  1121  returns to step S 1193  and awaits further response messages. 
     Meanwhile, if response messages have been acquired from all of the control-compliant appliances  125 , the appliance management unit  1121  implements a batch authentication process (step S 1197 ). If the batch authentication process succeeds for all of the control-compliant appliances, the appliance management unit  1121  judges that the authentication succeeded and the batch authentication process ends normally. 
     If the batch authentication process has not succeeded for all of the control-compliant appliances  125 , the appliance management unit  1121  specifies the control-compliant appliances for which the authentication failed in accordance with strategy 1 or strategy 2 described earlier (step S 1201 ). After this, the appliance management unit  1121  repeats the authentication process excluding the appliances for which the authentication failed (step S 1203 ), returns to step S 1199 , and judges whether the batch authentication process succeeded. 
     By carrying out processing in the flow described above, it is possible in the present example modification to efficiently authenticate the control-compliant appliances. 
     The above explanation describes a method that carries out authentication efficiently by grouping control-compliant appliances and power storage apparatuses using a batch verification or aggregate signature technique out of public key encryption-based digital signature techniques. However, although public key encryption has a merit compared to common key encryption in that it is possible to use digital signatures and the like generated using individual secret keys, there is also a demerit in that the computational load is normally extremely large. 
     To overcome such demerit, it is conceivably possible to use both public key encryption and common key encryption. More specifically, the power management apparatus  11  carries out authentication of the control-compliant appliances and the like based on public key encryption. It is assumed that the power management apparatus (or the control unit of the battery or the like) then provides common keys on 1:1 basis (i.e., a different key for each control-compliant appliance) for use by the power management apparatus (or the control unit of the battery or the like) and control-compliant appliances to control-compliant appliances and/or power storage apparatuses for which authentication based on public key encryption was successful. 
     Such common keys have a valid period such as one day or one hour, with such common keys being used for authentication processes carried out by the power management apparatus  11  on control-compliant appliances during the valid period. Also, after the valid period of a common key has ended, the authentication process is carried out again using public key encryption and a new common key is established between the power management apparatus and the control-compliant appliance. 
     By using this method, it is possible to carry out a process that uses public key encryption whose computational load is large only once an hour or once a day and to use common key encryption whose processing load is light for authentication that is carried out frequently. 
     Note that instead of using a common key on a 1:1 basis between the power management apparatus  11  and a certain control-compliant appliance  125 , it is also possible to share a single group key between a power management apparatus and a plurality of control-compliant appliances to be authenticated by the power management apparatus and to use the group key as a common key in subsequent authentication processes. 
     This completes the description of the method of registering control-compliant appliances according to the present example modification. 
     A process carried out by the power management apparatus for a managed appliance where an abnormality has occurred will now be described in detail while giving specific examples. 
     (1-16) Operation of Power Management Apparatus for Managed Appliance where Abnormality has Occurred 
     Operation of a power management apparatus for a managed appliance where an abnormality has occurred will now be described in detail with reference to  FIGS. 49 to 52  using specific examples.  FIGS. 49 to 52  are flowcharts useful in explaining the operation of the power management apparatus for a managed appliance where an abnormality has occurred. 
     First, the overall flow of the operation of the power management apparatus for a managed appliance where an abnormality has occurred will be described with reference to  FIG. 49 . 
     The appliance management unit  1121  of the power management apparatus  11  refers to time information relating to the present time or information relating to how much time has elapsed since a previous operation confirmation process was carried out and judges whether a time (check time) when the operation confirmation process is to be carried out on managed appliances has been reached (step S 1211 ). If the check time has not been reached, the appliance management unit  1121  returns to step S 1211  and awaits the check time to be reached. 
     Also, when the check time has been reached, the managed appliance information acquiring unit  1507  of the appliance management unit  1121  judges whether sensor information that reports the occurrence of an abnormality has been received from each control-compliant appliance  125  (step S 1213 ). If sensor information that reports the occurrence of an abnormality has been received, the appliance management unit  1121  implements step S 1225 , described later. 
     If sensor information that reports the occurrence of an abnormality has not been received, the managed appliance information acquiring unit  1507  judges whether appliance information that reports the occurrence of an abnormality has been received from the power distribution apparatus  121  (step S 1215 ). If appliance information that reports the occurrence of an abnormality has been received, the appliance management unit  1121  implements step S 1225 , described later. 
     If appliance information that reports the occurrence of an abnormality in the power distribution apparatus has not been received, the managed appliance information acquiring unit  1507  judges whether appliance information that reports the occurrence of an abnormality has been received from the control-compliant outlet  123  (which hereinafter includes the outlet expansion apparatus  127 ) (step S 1217 ). If it is judged that an abnormality has occurred, the appliance management unit  1121  implements step S 1225 , described later. 
     Note that by carrying out the processing in step S 1215  and step S 1217 , the power management apparatus  11  is capable of judging whether an abnormality has occurred in the non-control-compliant appliance  126  that is not capable of direct communication with the power management apparatus  11 . 
     Next, the managed appliance information acquiring unit  1507  gathers appliance information such as sensor information, battery information, and cell information from the respective control-compliant appliances and the like and transfers the appliance information to the appliance state judging unit  1601  and the power state judging unit  1603  of the information analyzing unit  1123 . The appliance state judging unit  1601  and the power state judging unit  1603  compare the appliance information with the history or model examples of the transferred information (step S 1219 ). By doing so, the power management apparatus  11  is able to detect abnormalities that have occurred at a control-compliant appliance or the like. The managed appliance information acquiring unit  1507  and/or the appliance state judging unit  1601  are also capable of detecting that an abnormality has occurred at a control-compliant appliance or the like from the non-reception of information that should have been received. 
     The appliance management unit  1121  refers to the result of the gathering/comparison process for the appliance information and judges whether a problem has occurred (step S 1221 ). If a problem has occurred, the appliance management unit  1121  implements step S 1225 , described later. 
     Also, if it has been judged from the result of the gathering/comparison process for the appliance information that a problem has not occurred, the appliance state judging unit  1601  judges whether no problems have occurred for any of the appliances (step S 1223 ). If, as a result of the judgment, verification has not been completed for some of the apparatuses, the appliance management unit  1121  and the information analyzing unit  1123  return to step S 1219  and continue the verification process. When verification has been completed for all of the appliances, the appliance management unit  1121  ends the verification process for the operation of the managed appliances. 
     Here, when an abnormality has been detected by the verification process described above, the information analyzing unit  1123  displays a warning on the display unit  116  (step S 1225 ). The power management apparatus  11  switches to an operation mode (error mode) used when an abnormality has been detected (step S 1227 ). 
     After this, the appliance management unit  1121  transmits a warning message to a registered telephone number or registered mail address of the user to inform the user that an abnormality has occurred (step S 1229 ). After this, the appliance management unit  1121  judges whether there has been a user access to the power management apparatus  11  within a set period (step S 1231 ). If there has been a user access within the set period, the control unit  115  of the power management apparatus  11  starts operation control of the control-compliant appliance based on a user indication (step S 1233 ). Meanwhile, if there has not been a user access within a set period, the control unit  115  of the power management apparatus  11  starts automatic control (step S 1235 ). After this, the control unit  115  of the power management apparatus  11  switches the operation mode to control by the control-compliant outlet (step S 1237 ) and ends the processing when an abnormal operation has been detected. 
     The specific processing implemented depending on the type of apparatus for which an abnormality has occurred will now be described in brief. 
     When Abnormality has Occurred at Power Management Apparatus 
     First, the operation when an abnormality has occurred at the power management apparatus  11  itself will be described in brief with reference to  FIG. 50 . 
     Note that it is assumed that before the following explanation begins, the user has already set what kind of control is to be carried out when an abnormality occurs at the power management apparatus  11  (as examples, control by a control-compliant outlet or control that supplies power in a steady state). It is also assumed that the power management apparatus  11  regularly backs up various information, such as history information, identification information (ID) of managed appliances, and setting conditions, in the system management server  33  provided outside the local power management system  1 . 
     When some kind of abnormality has occurred at the power management apparatus  11  itself (step S 1241 ) and the power management apparatus  11  itself stops working, since the regular communication with the power management apparatus  11  will stop, it is possible for the system management server  33  to detect that an abnormality has occurred at the power management apparatus  11  (step S 1243 ). 
     After this, the system management server  33  refers to the emergency contact or the like that has been registered and informs the user that an abnormality has occurred (step S 1245 ). 
     Since regular communication with the power management apparatus  11  is disabled (step S 1247 ), the control-compliant outlet  123  and the control-compliant appliance  125  also detect the possibility that an abnormality has occurred at the power management apparatus  11 . After this, the control-compliant outlet  123  and the control-compliant appliance  125  check the state of the power management apparatus  11  (step S 1249 ), and on grasping that an abnormality has occurred at the power management apparatus  11 , the control-compliant outlet  123  and the control-compliant appliance  125  check which mode is to be switched to (step S 1251 ). After this, the control-compliant outlet  123  and the control-compliant appliance  125  switch to control-compliant outlet control mode (step S 1253 ). 
     More specifically, the control-compliant outlet  123  starts controlling the control-compliant appliance  125  and the non-control-compliant appliance  126  (step S 1255 ) and the control-compliant appliance  125  starts outputting power information to the control-compliant outlet  123  (step S 1257 ). If an abnormality is detected in the power information acquired from the control-compliant appliance  125 , the control-compliant outlet  123  is also capable of implementing control, such as stopping the supplying of power. 
     At this point, it is assumed that the power management apparatus  11  has been restored due to the user who has been contacted from the system management server  33  reactivating the power management apparatus  11  or carrying out some kind of operation manually on the power management apparatus  11  (step S 1259 ). 
     At this point, the appliance management unit  1121  of the restored power management apparatus  11  requests the system management server  33  to implement the authentication process (step S 1261 ). If the authentication of the power management apparatus  11  succeeds, the system management server  33  acquires setting information that has been backed up and sends the setting information to the power management apparatus  11  (step S 1263 ). 
     The power management apparatus  11  that has received the setting information automatically connects to the control-compliant outlet  123  and the control-compliant appliance  125  that are managed apparatuses in accordance with the received setting information (step S 1265 ), and informs such appliances that the power management apparatus  11  has been restored. 
     After this, the control-compliant outlet  123  and the control-compliant appliance  125  switch to power management apparatus control mode (step S 1267 ) and thereafter normal control is carried out by the power management apparatus  11 . 
     When Abnormality has Occurred at Control-Compliant Outlet 
     Next, the operation when an abnormality has occurred at a control-compliant outlet  123  will be described in brief with reference to  FIG. 51 . 
     First, it is assumed that an abnormality has occurred at least one of a sensor or a communication unit of the control-compliant outlet  123  (step S 1271 ). In this case, since the supplying of power from the control-compliant outlet  123  to a connected control-compliant appliance  125  is maintained (step S 1273 ), it is difficult for the power management apparatus  11  to directly detect the abnormality. However, by determining that appliance information from the control-compliant outlet  123  that should be regularly received has not been received or the like, the power management apparatus  11  is able to detect that an abnormality has occurred at the control-compliant outlet  123  (step S 1275 ). 
     The information analyzing unit  1123  of the power management apparatus  11  that detected the abnormality informs the user that an abnormality has occurred at the control-compliant outlet  123  (step S 1277 ). More specifically, the power management apparatus  11  informs the user that an abnormality has occurred by displaying that an abnormality has occurred on the display unit  116 , emitting a warning sound, or transmitting a message to a telephone number or e-mail address registered by the user. 
     By carrying out an arbitrary operation manually on the control-compliant outlet  123  for which a problem has occurred, the user that has been informed restores the control-compliant outlet  123  to a functioning state (step S 1279 ). 
     Here, it is assumed that an abnormality has occurred for the power supply control of the control-compliant outlet  123  (step S 1281 ). In this case, the control-compliant appliance  125  is capable of detecting that an abnormality has occurred at the control-compliant outlet  123  and in some cases, it is also possible for the control-compliant appliance  125  to stop receiving the supplying of power and therefore stop operating (step S 1283 ). As a result, due to the control-compliant appliance  125  informing the power management apparatus  11  that an abnormality has occurred at the control-compliant outlet  123  or due to regular communication stopping because of the operation of the control-compliant appliance  125  stopping, the power management apparatus  11  detects that an abnormality has occurred (step S 1285 ). 
     The information analyzing unit  1123  of the power management apparatus  11  that has detected the abnormality informs the user that an abnormality has occurred at the control-compliant outlet  123  (step S 1287 ). More specifically, the power management apparatus  11  informs the user that an abnormality has occurred by displaying that an abnormality has occurred on the display unit  116 , emitting a warning sound, or transmitting a message to a telephone number or e-mail address registered by the user. 
     By carrying out an operation manually on the control-compliant outlet  123  for which a problem has occurred, the user that has been informed restores the control-compliant outlet  123  to a functioning state (step S 1289 ). 
     When Abnormality has Occurred at Power Distribution Apparatus 
     Next, the operation when an abnormality has occurred at the power distribution apparatus  121  will be described in brief with reference to  FIG. 52 . 
     When an abnormality has occurred at the power distribution apparatus  121  (step S 1301 ), the power distribution apparatus  121  informs the power management apparatus  11  that an abnormality has occurred and/or regular communication from the power distribution apparatus  121  stops. Also, when an abnormality has occurred at the power distribution apparatus  121 , there is the possibility of a problem occurring for the supplying of power to a control-compliant appliance  125 . For this reason, an abnormality may also occur in the power information (step S 1303 ) transmitted regularly by the control-compliant appliance  125 . From such information, the information analyzing unit  1123  of the power management apparatus  11  can detect that an abnormality has occurred at the power distribution apparatus  121  (step S 1305 ). 
     The information analyzing unit  1123  of the power management apparatus  11  that has detected the abnormality informs the user that an abnormality has occurred at the power distribution apparatus  121  (step S 1307 ). More specifically, the power management apparatus  11  informs the user that an abnormality has occurred by displaying that an abnormality has occurred on the display unit  116 , emitting a warning sound, or transmitting a message to a telephone number or e-mail address registered by the user. 
     By carrying out an operation manually on the power distribution apparatus  121  for which a problem has occurred, the user that has been informed restores the power distribution apparatus  121  to a functioning state (step S 1309 ). 
     An abnormality occurs again at the power distribution apparatus  121  (step S 1311 ), and the power distribution apparatus  121  informs the power management apparatus  11  that an abnormality has occurred and/or regular communication from the power distribution apparatus  121  stops. Also, when an abnormality has occurred at the power distribution apparatus  121 , there is the possibility of a problem occurring for the supplying of power to the control-compliant appliance  125 . For this reason, an abnormality may also occur for the power information (step S 1313 ) transmitted regularly by the control-compliant appliance  125 . Due to such information, it is assumed that an abnormality also occurs in the power management apparatus  11  itself (step S 1317 ). 
     Here, the break in regular communication with the power management apparatus  11  makes it possible for the system management server  33  to detect that an abnormality has occurred at the power management apparatus  11  (step S 1319 ). 
     After this, the system management server  33  refers to the emergency contact or the like that has been registered and informs the user that an abnormality has occurred (step S 1321 ). 
     In this case, at the power management apparatus  11 , a process described earlier that is carried out when an abnormality has occurred in the power management apparatus is implemented (step S 1323 ). In response to the abnormality occurring at the power management apparatus  11 , the control-compliant appliance  125  switches to control-compliant outlet control mode (step S 1325 ). 
     Here, by carrying out an operation manually on the power distribution apparatus  121  for which a problem has occurred, the user that has been informed restores the power distribution apparatus  121  to a functioning state (step S 1327 ). Also, due to the operation carried out when an abnormality occurred at the power management apparatus, the power management apparatus  11  is also restored to a functioning state (step S 1327 ). 
     This completes the description of the operation of the power management apparatus  11  when an abnormality has occurred for a managed apparatus such as a control-compliant outlet  123  or a control-compliant appliance  125 . 
     (1-17) Operation of Power Management Apparatus when Abnormality has Occurred in Power State 
     Next, the operation of the power management apparatus  11  when an abnormality, such as a power cut or a leak, has occurred in the power state in the local power management system  1  will be described with reference to  FIGS. 53 and 54 .  FIGS. 53 and 54  are flowcharts useful for explaining the operation of the power management apparatus when an abnormality has occurred in the power state. 
     Operation of Power Management Apparatus During Power Cut 
     First, the operation of the power management apparatus when a power cut has occurred will be described in brief with reference to  FIG. 53 . 
     When an abnormality has occurred for external power and a power cut occurs, the supplying of external power to the power distribution apparatus  121  stops. As a result, due to the power distribution apparatus  121  informing the power management apparatus  11  that a power cut has occurred or appliance information including an abnormality being transmitted from the power distribution apparatus  121 , the power management apparatus  11  can detect the abnormality at the power distribution apparatus  121  (step S 1331 ). 
     On detecting that a power cut has occurred, the power state judging unit  1603  of the information analyzing unit  1123  switches the current mode to a power supplying mode (stored power supplying mode) that uses the power generating apparatuses  129 ,  130  and the power storage apparatus  128  (step S 1333 ). More specifically, the control unit  115  of the power management apparatus  11  transmits a control command to the power distribution apparatus  121  for switching from external power to power that is capable of being supplied within the system  1 . The appliance management unit  1121  starts processing that determines priorities for supplying power and/or determines amounts of power to be distributed based on information set in advance. The information analyzing unit  1123  also informs the user that a power cut has occurred via the display unit  116  or the like. 
     The appliance management unit  1121  first judges whether an appliance to be supplied power is a control-compliant appliance  125  (step S 1335 ). If the appliance to be supplied power is a control-compliant appliance  125 , the appliance management unit  1121  transmits a control command to the appliance via the control unit  115  (step S 1337 ). More specifically, the control unit  115  transmits a control command that requests power save mode or power off to the control-compliant appliance  125  in question. 
     Meanwhile, if the appliance to be supplied power is not a control-compliant appliance  125  (that is, a non-control-compliant appliance  126 ), the appliance management unit  1121  judges whether the appliance to be supplied power is connected to a control-compliant outlet  123  (including the outlet expansion apparatus  127 ) (step S 1339 ). If the appliance to be supplied power is connected to a control-compliant outlet  123 , the appliance management unit  1121  transmits a control command to the control-compliant outlet  123  via the control unit  115  (step S 1341 ). More specifically, the control unit  115  transmits a control command that requests power off for the appliance to be supplied power (that is, the stopping of the supplying of power to the non-control-compliant appliance  126 ) to the control-compliant outlet  123 . 
     If the appliance to be supplied power is not connected to a control-compliant outlet  123 , since the power management apparatus  11  is not able to control the supplying of power to the appliance to be supplied power, the power management apparatus  11  leaves the appliance as it is or continues the present supplying of power (step S 1343 ). 
     When this determination has ended, the appliance management unit  1121  judges whether the setting of every appliance has been completed (step S 1345 ). If the settings of one or more appliances have not been completed, the power management apparatus  11  returns to step S 1335  and continues the processing. Meanwhile, if the settings of all of the appliances have been completed, the power management apparatus  11  ends the processing during a power cut. 
     Operation of Power Management Apparatus During a Leak 
     Next, the operation of the power management apparatus when a power leak has occurred will be described in brief with reference to  FIG. 54 . 
     When a power leak occurs, it is expected that the tendency of power usage will change compared to before the leak occurred. Accordingly, by comparing a history of past power usage with the present power usage, the power state judging unit  1603  of the information analyzing unit  1123  in the power management apparatus  11  is capable of detecting that a power leak has occurred (step S 1351 ). Also, for appliances present in the system  1 , the power state judging unit  1603  calculates a power usage theoretical value based on a theoretical value of the power usage of control-compliant appliances  125  and estimated power usage of the non-control-compliant appliances  126 , and by comparing the actual power usage and the power usage theoretical value, it is possible to detect a power leak. Note that the estimated power usage of the non-control-compliant appliance  126  can be estimated from past usage. 
     Also, the occurrence of a power leak may be detected not only by the power management apparatus  11  but also by the analysis server  34  such as a security check server that is present outside the local power management system  1 . This means that in some cases when a power leak has occurred, the analysis server  34  informs the power management apparatus  11  of the leak. 
     When the occurrence of a leak has been detected, the power management apparatus  11  specifies the leak location using an arbitrary method (step S 1353 ) and the control unit  115  transmits a power supplying stop command to the leak location (step S 1355 ). The information analyzing unit  1123  also displays information relating to the occurrence of the leak and the leak location on the display unit  116  (step S 1357 ). 
     By carrying out such processing, even when an abnormality has occurred for the power state such as a power cut or a power leak, the power management apparatus  11  is capable of maintaining various aspects of security inside the local power management system  1 . 
     (1-18) Flow of Method of Embedding and Method of Verifying Electronic Watermark Information 
     Next, the flow of a method of embedding and method of verifying electronic watermark information carried out in the local power management system  1  according to the present embodiment will be described with reference to  FIGS. 55 to 58 .  FIGS. 55 and 57  are flowcharts useful in explaining the method of embedding the electronic watermark information according to the present embodiment.  FIGS. 56 and 58  are flowcharts useful in explaining the method of method verifying the electronic watermark information according to the present embodiment. 
     Method of Embedding and Method of Verifying Electronic Watermark Information that Uses Shared Information 
     First, the flow of the method of embedding and method of verifying electronic watermark information that uses shared information will be described with reference to  FIGS. 55 and 56 . Note that a case where the physical data itself is used as the appliance characterizing information is described below. 
     Flow of Method of Embedding 
     First, a method of embedding implemented by the tampering detection information generating unit  2031  of the control-compliant appliance  125  will be described with reference to  FIG. 55 . 
     The appliance characterizing information generating unit  2033  of the tampering detection information generating unit  2031  in the control-compliant appliance  125  first acquires physical data from the sensor control unit  2023  and the battery control unit  2027  (step S 2001 ). After this, the appliance characterizing information generating unit  2033  carries out verification on the acquired physical data (step S 2003 ). Next, the appliance characterizing information generating unit  2033  judges whether the acquired physical data is normal (step S 2005 ). 
     If the verification finds that a value of the physical data exceeds a range of values that can be taken by the physical data or shows what is clearly abnormal behavior, the appliance characterizing information generating unit  2033  reports an abnormality (step S 2019 ). 
     After it has been confirmed via the verification that the physical data is normal, the electronic watermark generating unit  2035  generates electronic watermark information based on the physical data and the shared data (step S 2007 ) and outputs the generated electronic watermark information to the electronic watermark embedding unit  2039 . The embedded position deciding unit  2037  analyzes the physical data, determines an embedded position of the electronic watermark information that is suitable for the physical data and informs the electronic watermark embedding unit  2039  of information relating to the decided embedded position. 
     After this, the electronic watermark embedding unit  2039  embeds the electronic watermark information in the physical data based on information relating to the embedded position (step S 2009 ). Next, the electronic watermark embedding unit  2039  carries out verification on the physical data in which the electronic watermark information has been embedded (such physical data is hereinafter referred to as “embedded data”) (step S 2011 ). After this, the electronic watermark embedding unit  2039  checks the verification result (step S 2013 ). 
     If the embedded data is normal, the electronic watermark embedding unit  2039  transmits the embedded data to the power management apparatus  11  (step S 2015 ). The power management apparatus  11  transmits the received embedded data to the analysis server  34  outside the local power management system  1 . 
     Meanwhile, if an abnormality has been found in the embedded data, the electronic watermark embedding unit  2039  judges whether the number of times an abnormality has occurred is under a specified threshold (step S 2017 ). If the number of times an abnormality has occurred is under a specified threshold, the tampering detection information generating unit  2031  returns to step S 2007  and the processing continues. Meanwhile, if the number of times an abnormality has occurred is equal to or greater than a specified threshold, the tampering detection information generating unit  2031  reports an abnormality (step S 2019 ). 
     Note that if the embedded position of the electronic watermark information is decided in advance, the process that decides the embedded position, the process that verifies the physical data in step S 2003  to step S 2005 , and the process that verifies the embedded data in steps S 2011  to steps S 2019  can be omitted. 
     Flow of Method of Verifying 
     Next, the method of verifying the electronic watermark information implemented by an information tampering detecting unit in the analysis server  34  such as a security check server will be described with reference to  FIG. 56 . Note that although a method of verification carried out on the analysis server  34  is described below, the same method may be carried out by an information tampering detecting unit of a power management apparatus. 
     An embedded position specifying unit of an information tampering detecting unit of the analysis server  34  acquires the physical data in which the electronic watermark information is embedded (step S 2021 ). After this, the embedded position specifying unit verifies the acquired physical data (step S 2023 ). Next, the embedded position specifying unit judges whether the acquired physical data is normal (step S 2025 ). 
     If the verification finds that a value of the physical data exceeds a range of values that can be taken by the physical data or shows what is clearly abnormal behavior, the embedded position specifying unit reports an abnormality (step S 2027 ). 
     After it has been confirmed via the verification that the physical data is normal, the embedded position specifying unit analyzes the physical data, specifies the position at which the electronic watermark information was embedded (step S 2029 ), and informs the electronic watermark extracting unit of position information relating to the embedded position. 
     Next, the electronic watermark extracting unit extracts the electronic watermark information from the physical data based on the received position information relating to the embedded position (step S 2031 ) and outputs the extracted electronic watermark information to the electronic watermark verification unit. 
     After this, the electronic watermark verification unit generates electronic watermark information based on the physical data and the shared data (step S 2033 ) and verifies the electronic watermark information by comparing the extracted electronic watermark information with the generated electronic watermark information (step S 2035 ). If the verification of the electronic watermark information based on the comparison has failed, the electronic watermark verification unit informs the power management apparatus  11  of an abnormality (step S 2027 ). Also, if the verification of the electronic watermark information based on the comparison has succeeded, the electronic watermark verification unit reports that the verification succeeded and the processing ends normally. 
     Note that if the embedded position of the electronic watermark information is decided in advance, the process that verifies the physical data in step S 2023  to step S 2025 , and the process that specifies the embedded position (step S 2029 ) can be omitted. 
     Method of Embedding and Method of Verifying Electronic Watermark Information that Uses Time Information and Shared Information 
     Next, a method of embedding and method of verifying electronic watermark information that uses time information and shared information will be described with reference to  FIGS. 57 and 58 . Note that a case where the physical data itself is used as the appliance characterizing information is described below. 
     Flow of Method of Embedding 
     First, a method of embedding implemented by the tampering detection information generating unit  2031  of the control-compliant appliance  125  will be described with reference to  FIG. 57 . 
     Note that it is assumed that the control-compliant appliance  125  transmits the physical data in which the electronic watermark information has been embedded regularly via the power management apparatus  11  to the analysis server  34  and that the data transmission timing is decided in advance between the control-compliant appliance  125  and the analysis server  34 . 
     The tampering detection information generating unit  2031  of the control-compliant appliance  125  judges whether the scheduled data transmission time has been reached (step S 2041 ). If the scheduled transmission time has not been reached, the tampering detection information generating unit  2031  awaits the scheduled time to be reached. If the scheduled transmission time has been reached, the appliance characterizing information generating unit  2033  acquires the physical data from the sensor control unit  2023  and the battery control unit  2027  (step S 2043 ). After this, the appliance characterizing information generating unit  2033  verifies the acquired physical data (step S 2045 ). Next, the appliance characterizing information generating unit  2033  judges whether the acquired physical data is normal (step S 2047 ). 
     If the verification finds that a value of the physical data exceeds a range of values that can be taken by the physical data or shows what is clearly abnormal behavior, the appliance characterizing information generating unit  2033  reports an abnormality (step S 2065 ). 
     After it has been confirmed via the verification that the physical data is normal, the embedded position deciding unit  2037  analyzes the physical data, determines an embedded position of the electronic watermark information that is suitable for the physical data (step S 2049 ), and informs the electronic watermark embedding unit  2039  of information relating to the decided embedded position. 
     Next, the electronic watermark generating unit  2035  acquires time information showing the present time or a transmission scheduled time (step S 2051 ). After this, the electronic watermark generating unit  2035  generates the electronic watermark information based on the physical data, time information, and shared information (step S 2053 ), and outputs the generated electronic watermark information to the electronic watermark embedding unit  2039 . 
     After this, the electronic watermark embedding unit  2039  embeds the electronic watermark information in the physical data based on information relating to the embedded position (step S 2055 ). Next, the electronic watermark embedding unit  2039  verifies the physical data in which the electronic watermark information is embedded (such physical data is hereinafter referred to as “embedded data”) (step S 2057 ). After this, the electronic watermark embedding unit  2039  checks the verification result (step S 2059 ). 
     If the embedded data is normal, the electronic watermark embedding unit  2039  transmits the embedded data to the power management apparatus  11  (step S 2061 ). The power management apparatus  11  transmits the received embedded data to the analysis server  34  outside the local power management system  1 . 
     Meanwhile, if an abnormality has been found in the embedded data, the electronic watermark embedding unit  2039  judges whether the number of times an abnormality has occurred is under a specified threshold (step S 2063 ). If the number of times an abnormality has occurred is under a specified threshold, the tampering detection information generating unit  2031  returns to step S 2053  and the processing continues. Meanwhile, if the number of times an abnormality has occurred is equal to or greater than a specified threshold, the tampering detection information generating unit  2031  reports an abnormality (step S 2065 ). 
     Note that if the embedded position of the electronic watermark information is decided in advance, the process that decides the embedded position, the process that verifies the physical data in step S 2045  to step S 2047 , and the process that verifies the embedded data in steps S 2057  to steps S 2063  can be omitted. 
     Flow of Method of Verifying 
     Next, the method of verifying the electronic watermark information implemented by an information tampering detecting unit in the analysis server  34  such as a security check server will be described with reference to  FIG. 58 . 
     Note that it is assumed that the control-compliant appliance  125  transmits the physical data in which the electronic watermark information has been embedded regularly via the power management apparatus  11  to the analysis server  34  and that the data transmission timing is decided in advance between the control-compliant appliance  125  and the analysis server  34 . 
     The information tampering detecting unit of the analysis server judges whether the scheduled data transmission time has been reached (step S 2071 ). If the scheduled transmission time has not been reached, the information tampering detecting unit awaits the scheduled time to be reached. If the scheduled transmission time has been reached, the information tampering detecting unit attempts to acquire physical data transmitted from the control-compliant appliance  125  via the power management apparatus  11 . Here, the information tampering detecting unit judges whether the physical data can be received within a specified time period (step S 2073 ). 
     If the physical data has not been received within the specified time period, the information tampering detecting unit informs the user of the power management apparatus  11  of an abnormality (step S 2089 ). Meanwhile, if physical data has been received within the predetermined time period, the embedded position specifying unit verifies the acquired physical data (step S 2075 ). After this, the embedded position specifying unit judges whether the acquired physical data is normal (step S 2077 ). 
     If the verification finds that a value of the physical data exceeds a range of values that can be taken by the physical data or shows what is clearly abnormal behavior, the embedded position specifying unit reports an abnormality (step S 2089 ). 
     After it has been confirmed via the verification that the physical data is normal, the embedded position specifying unit analyzes the physical data, specifies the position at which the electronic watermark information was embedded (step S 2079 ), and informs the electronic watermark extracting unit of position information relating to the embedded position. The electronic watermark extracting unit extracts the electronic watermark information from the physical data based on the position information relating to the embedded position and outputs the extracted electronic watermark information to the electronic watermark verification unit. 
     After this, the electronic watermark verification unit obtains time information showing the present time or transmission scheduled time (step S 2081 ). 
     After this, the electronic watermark verification unit generates electronic watermark information based on the physical data, the time information, and the shared data (step S 2083 ) and compares the extracted electronic watermark information with the generated electronic watermark information to verify the electronic watermark information (step S 2085 ). If the verification of the electronic watermark information based on the comparison has failed, the electronic watermark verification unit reports an abnormality (step S 2089 ). Also, if the verification of the electronic watermark information based on the comparison has succeeded, the electronic watermark verification unit reports that the verification succeeded and the processing ends normally. 
     Note that if the embedded position of the electronic watermark information is decided in advance, the process that verifies the physical data in step S 2075  to step S 2077 , and the process that specifies the embedded position (step S 2079 ) can be omitted. 
     By carrying out the processing described above, it is possible to detect an abnormality when the control function of a power management apparatus  11  positioned between the analysis server  34  and the control-compliant appliance  125  has been compromised. By using the electronic watermark information, it is also possible to detect tampering with the physical data carried out by an attacker on a communication path. In addition, the power management apparatus  11  merely mediates the transferring of the physical data, and it is possible to detect tampering with the physical data on the path between the analysis server  34  and the control-compliant appliance  125  without having to transmit or receive special data for preventing tampering. 
     Even when the control function of the power management apparatus  11  has been compromised, it is possible to prevent attacks where an attacker tampers with the physical data. In addition, by using this method, it is possible to append a function for detecting tampering to the physical data without the statistical nature of the physical data being lost. 
     (1-19) Role of Analysis Server 
     The power management apparatus  11  that functions as a power center in the local power management system  1  is connected to various control-compliant appliances and the like that are equipped with batteries. The power management apparatus  11  controls the distributing of power by controlling the power distribution apparatus  121  based on power information obtained from the various appliances. The power management apparatus  11  is capable of grasping the power consumption of appliances connected to the system  1  in real time and collectively manages the power usage state inside the system  1  including power produced by home generation of natural energy, such as photovoltaic generation. The power management apparatus  11  is also capable of visualizing power consumption, which is expected to lead to the user suppressing wasteful consumption of energy. 
     However, since the local power management system  1  is a network system that controls a local power network, it is important to use security techniques in the system configuration and services. In recent years, for appliances that are equipped with batteries, it has become commonplace for users to replace the battery cells with inferior products and/or use counterfeit chips that bypass authentication with the appliance. This can lead to problems, such as the drop in quality causing fires. The “batteries” handled by the local power management system  1  according to the present embodiment include various apparatuses such as power storage apparatuses and electric vehicles present in the system, and it is important to maintain safety for such apparatuses. 
     The following are some conceivable examples of external attacks that can be implemented on the power management apparatus  11  that forms an interface between the outside of the local power management system  1  and the inside of the system  1 .
         the introduction of illegal commands (a virus) that cause an appliance or battery to operate abnormally   taking over control of the power management apparatus   a Trojan horse attack   an attack on another appliance or system via the power management apparatus   a DoS attack       

     To protect against such external attacks, the measures listed below have been used in the past.
         preventing illegal operations that are predicted in advance   detecting viruses using a virus pattern file defined in advance   monitoring behavior of execution files and detecting illegal files to protect against unknown attacks       

     However, since such measures are used in response to behavior on a computer, it is difficult to use such measures to monitor a physical device such as a battery, and it is therefore difficult to say such measures provide sufficient protection. Also, since it is thought that the batteries and appliances that can be connected to the power management apparatus will be frequently updated, there is a high probability that the countermeasures against attacks will become extremely complex and it will be difficult to imagine the content of attacks in advance. 
     One countermeasure against counterfeit batteries is to incorporate an authentication chip into a battery module and to only connect to batteries whose quality is guaranteed. However, in recent years, techniques for invalidating the functions of an authentication chip have advanced and cases where counterfeit chips bypass authentication are becoming widespread. If a battery state (voltage, current, remaining charge, or the like) transmitted via an appliance from a counterfeit chip mounted on inferior battery cells is not correct (i.e., if the digital information is erroneous), the power management apparatus will not be capable of correctly controlling the power network, resulting in a high risk of accidents. In this situation, the operation of the appliance should be stopped or the problematic batteries should be excluded, but there is no existing technology to achieve such a mechanism. 
     For the above reason, a technique for avoiding attacks (virus infections) on appliances/batteries connected to the power management apparatus or system and the risks that accompany battery deterioration or counterfeit products is necessary. A method that is capable of detecting the presence of the kind of attacks described above on the system or deterioration and the like of batteries using sensor information, which is outputted from the batteries or appliances connected to the system, and various types of history information is described below. 
     The method of detecting the presence of attacks and deterioration and the like of batteries described below mainly uses physical data such as sensor information and the like outputted from the respective appliances and history information to make judgments using calculating physical estimates and high-speed judgments using a heuristic statistical method. By doing so, it is possible to detect unknown attacks and to avoid risks from the outset. 
     In the present embodiment, the analysis server  34  provided outside the local power management system  1  is used as an apparatus for detecting attacks and avoiding risks. It is assumed that one of the functions of the analysis server  34  is a function that carries out a security check on the local power management systems. Accordingly, the analysis server  34  described below is a server that functions as a security check server. 
     The analysis server  34  realizes the functions listed below based on sensor information of various appliances and batteries transmitted from a power management apparatus, execution command information, appliance/battery information registered in advance in the analysis server  34 , usage environment information, and usage history information.
         exclude copies that bypass authentication and batteries that have deteriorated and whose operation is dangerous   protect against heuristic external attacks   verify validity via an estimate based on the present state, inputs, and information on external environment   generate and update a virus definition file used by an antivirus system in the power management apparatus       

     Also, as described above, the analysis server  34  is capable of being further equipped with a function that verifies tampering detection information (electronic watermark information) embedded in appliance characterizing information transmitted from various appliances and batteries. By using the tampering detection information, it is also possible to check whether a power management apparatus has been taken over. 
     Here, voltage, current, temperature, humidity, time, usage appliance information, user, and the like can be given as examples of the sensor information mentioned above, and instruction commands, execution files, appliance/battery parameters and the like can be given as examples of execution command information. Also, manufacturer, model number, manufacturer number, and the like can be given as examples of the appliance/battery information registered in advance in the analysis server  34 , and family information, location, owned appliance information, and the like can be given as examples of the usage environment information. Past appliance/battery sensor information, execution command information, usage time, usage frequency, and the like can be given as examples of the usage history information mentioned above. 
     (1-20) Configuration of Analysis Server 
     Next, the configuration of the analysis server  34  that is a security check server according to the present embodiment will be described in detail with reference to  FIGS. 59 to 62 .  FIG. 59  is a block diagram useful in explaining the configuration of an analysis server according to the present embodiment.  FIG. 60  is a block diagram useful in explaining the configuration of an information tampering detecting unit included in the analysis server according to the present embodiment.  FIG. 61  is a block diagram useful in explaining the configuration of a first verification unit included in the analysis server according to the present embodiment.  FIG. 62  is a block diagram useful in explaining the configuration of a second verification unit included in the analysis server according to the present embodiment. 
     Overall Configuration of Analysis Server 
     First, the overall configuration of the analysis server  34  according to the present embodiment will be described with reference to  FIG. 59 . 
     As illustrated in  FIG. 59 , the analysis server  34  according to the present embodiment mainly includes a wide area communication unit  3001 , an information tampering detecting unit  3003 , an acquired data verification unit  3005 , and a storage unit  3013 . 
     The wide area communication unit  3001  is communication means for exchanging information between the local power management system  1  and another server or the like via a wide area network  2 . 
     The information tampering detecting unit  3003  is realized by a CPU, a ROM, a RAM, and the like, for example. When data for detecting whether information has been tampered with is embedded in the information acquired by the analysis server  34  from the power management apparatus  11 , the information tampering detecting unit  3003  verifies the data and detects whether the information has been tampered with. Here, an electronic watermark can be given as one example of data embedded in such information. 
     When tampering with the information has been detected, the information tampering detecting unit  3003  informs the power management apparatus  11  or the user himself/herself of the detection result. By doing so, the power management apparatus  11  or the user of the power management apparatus  11  is capable of excluding the appliance where tampering with information has occurred from inside the system  1 . 
     The acquired data verification unit  3005  is realized by a CPU, a ROM, a RAM, and the like, for example. The acquired data verification unit  3005  verifies various information acquired from the power management apparatus  11  and as described earlier, is a processing unit that provides various functions for protecting the power management apparatus  11  from external attacks. 
     As shown in  FIG. 59 , the acquired data verification unit  3005  further includes an acquired data verification control unit  3007 , a first verification unit  3009 , and a second verification unit  3011 . 
     The acquired data verification control unit  3007  carries out control when various data acquired by the analysis server  34  from the power management apparatus  11  is analyzed and verified. More specifically, the acquired data verification control unit  3007  judges how to combine verification by the first verification unit  3009  and verification by the second verification unit  3011  described later to analyze and verify the acquired data. Accordingly, the first verification unit  3009  and the second verification unit  3011  described later carry out various verification processing under the control of the acquired data verification control unit  3007 . 
     The first verification unit  3009  is realized by a CPU, a ROM, a RAM, and the like, for example. The first verification unit  3009  analyzes and verifies various types of information acquired by the analysis server  34  using a heuristic method based on statistical processing. 
     The first verification unit  3009  mainly has the two functions described below.
     (i) A function that detects the presence of attacks to the power management apparatus, abnormalities at a battery or various appliances or sensors by comparing the data acquired from a power management apparatus with data acquired from another power management apparatus that has a similar power usage environment.   (ii) A function that detects the presence of attacks to the power management apparatus, abnormalities at a battery or various appliances or sensors in data acquired from a power management apparatus from a comparison with previous usage history data.   

     To realize the function (i) given above, the first verification unit  3009  uses the “battery model number/ID information and power status information, history” and “appliance model number/ID information and sensor information such as temperature, history” or “execution file of power management apparatus” acquired from the power management apparatus  11  being verified. The first verification unit  3009  uses not only the information mentioned above acquired from the power management apparatus being verified but also the information mentioned above acquired from other power management apparatuses  11  that are not being verified. By comparing and verifying such data, the first verification unit  3009  determines whether there has been an attack on the power management apparatus being verified and/or whether there is an abnormality at a battery/appliance or sensor. 
     To realize the function (ii) given above, the first verification unit  3009  acquires the “battery model number/ID information and power status information” and “appliance model number/ID information and sensor information such as temperature” or “execution file of power management apparatus” from the power management apparatus  11  being verified. The first verification unit  3009  also uses the “battery power status information history”, “sensor information history of appliances”, and “execution file history of power management apparatus” of the power management apparatus  11  being verified. By comparing and verifying such data, the first verification unit  3009  determines whether there has been an attack on the power management apparatus being verified and/or whether there is an abnormality at a battery/appliance or sensor. 
     The first verification unit  3009  further includes a function that verities the command information in the “execution file of the power management apparatus” and is operable when the command information is determined to be abnormal to extract a virus pattern from the command information determined to be abnormal. The first verification unit  3009  uses the extracted virus pattern and generates a virus definition file relating to such virus. 
     On determining that there is an abnormality in the sensor information of the appliance, the execution file, the command information, or the like, the first verification unit  3009  may share such information with the second verification unit  3011  or may transmit such information to the second verification unit  3011 . By sharing or transmitting such information, it becomes possible for the second verification unit to update the parameters used in a simulation and possible to further improve the simulation precision. 
     The second verification unit  3011  is realized by a CPU, a ROM, a RAM, and the like, for example. The second verification unit  3011  analyzes and verifies the various information acquired by the analysis server  34  by simulation (calculating physical estimates) using the acquired data. 
     The second verification unit  3011  mainly includes a function that detects an abnormality at the battery/appliance or sensor through a highly precise judgment achieved by calculating estimates of physical amounts. 
     The second verification unit  3011  acquires “battery model number/ID information and power status information, history” and “appliance model number/ID information and sensor information such as temperature, history” in the system  1  from the power management apparatus  11  being verified. In addition, the second verification unit  3011  acquires electrical specifications and characteristic information of the batteries/appliances from the power management apparatus  11  being verified. The second verification unit  3011  carries out simulation based on the acquired appliance information, electrical specifications and characteristic information, and also the usage history information to calculate indices (hereinafter, “normal operating ranges”) showing that such appliances are operating appropriately. The second verification unit  3011  compares and verifies the calculated normal operating ranges and the various data mentioned above that has been acquired and judges whether there has been an attack on the power management apparatus being verified and whether there is an abnormality at a battery/appliance or sensor. 
     The storage unit  3013  is one example of a storage apparatus provided in the analysis server  34  according to the present embodiment. The storage unit  3013  stores information relating to various keys stored by the analysis server  34 , and various digital signatures, certificates, and the like stored by the analysis server  34 . Various history information may also be recorded in the storage unit  3013 . In addition, the storage unit  3013  may also store, as appropriate, various parameters and intermediate progress of processing that should be stored during processing by the analysis server  34  according to the present embodiment, or various databases and the like. The various processing units of the analysis server  34  are capable of freely reading from and writing into the storage unit  3013   
     Configuration of Information Tampering Detecting Unit 
     Next, the configuration of the information tampering detecting unit  3003  will be described with reference to  FIG. 60 . 
     As shown in  FIG. 60 , the information tampering detecting unit  3003  also includes an embedded position specifying unit  3021 , an electronic watermark extracting unit  3023 , and an electronic watermark verifying unit  3025 . 
     With the local power management system  1  according to the present embodiment, it is possible to embed, into physical data such as current, voltage, temperature, and humidity, or into various information calculated using such physical data, electronic watermark data that is suited to such information. By verifying the electronic watermark data, the analysis server  34  that is capable of two-way communication with the local power management system  1  are capable of detecting whether the physical data (which hereinafter includes various information calculated using physical data) has been tampered with. 
     The embedded position specifying unit  3021  is realized by a CPU, a ROM, a RAM, and the like, for example. By analyzing the physical data in which the electronic watermark has been embedded using a predetermined signal processing circuit, the embedded position specifying unit  3021  specifies the embedded position of the electronic watermark information in accordance with the characteristics of a signal corresponding to the data. On specifying the embedded position of the electronic watermark information, the embedded position specifying unit  3021  informs the electronic watermark extracting unit  3023  of information relating to the specified embedded position. Note that if the embedded position of the electronic watermark is determined in advance between a control-compliant appliance  125  or the like and the analysis server  34 , it may not be necessary to carry out the specifying process for the embedded position. 
     The electronic watermark extracting unit  3023  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark extracting unit  3023  extracts the electronic watermark information from the physical data based on information relating to the embedded position provided by the embedded position specifying unit  3021 . The electronic watermark extracting unit  3023  transfers the electronic watermark extracted from the physical data to the electronic watermark verifying unit  3025 , described later. 
     The electronic watermark verifying unit  3025  is realized by a CPU, a ROM, a RAM, and the like, for example. The electronic watermark verifying unit  3025  first generates electronic watermark information based on shared information shared with the control-compliant appliance  125  or the like and physical data extracted by the electronic watermark extracting unit  3023 . To generate the electronic watermark information, a hash function, a pseudorandom number generator, common key encryption, shared key encryption (for example, a message authentication code (MAC)), or the like is used. After this, the electronic watermark verifying unit  3025  compares the generated electronic watermark information and the electronic watermark information extracted by the electronic watermark extracting unit  3023 . 
     If the generated electronic watermark information and the extracted electronic watermark information are the same, the electronic watermark verifying unit  3025  judges that the physical data or the like generated by the control-compliant appliance  125  or the like has not been tampered with. Meanwhile, if the generated electronic watermark information and the extracted electronic watermark information are not the same, the electronic watermark verifying unit  3025  judges that the physical data has been tampered with. 
     If the physical data has been tampered with, the electronic watermark verifying unit  3025  informs the power management apparatus  11  or the user himself/herself. By doing so, the power management apparatus  11  or the user himself/herself become able to exclude a control-compliant appliance  125  or the like whose operation may have been modified from the local power management system  1 . 
     Furthermore, if the electronic watermark information is generated by using not only the physical data and the shared information but also the time information, it becomes possible also to verify whether the power management apparatus managing the local power management system  1  is taken over or not, as described earlier. 
     Configuration of First Verifying Unit 
     Next, the configuration of the first verification unit  3009  will be described in detail with reference to  FIG. 61 . 
     As described above, the first verification unit  3009  extracts characterizing amounts based on sensor information and execution command information of batteries and appliances transmitted from the power management apparatus  11 , information on the batteries and appliances registered in advance in the analysis server  34 , usage environment information, and usage history information. After this, the first verification unit  3009  detects differences and abnormalities at high speed based on the extracted characterizing amounts. 
     As shown in  FIG. 61 , the first verification unit  3009  includes a verification control unit  3031 , an operation judging unit  3033 , a database management unit  3035 , a virus definition file management unit  3037 , and a shared information generating unit  3039 . The first verification unit  3009  further includes a power management apparatus database  3041 , a judgment dictionary  3043 , and a virus definition file database  3045 . 
     The verification control unit  3031  is realized by a CPU, a ROM, a RAM, and the like, for example. The verification control unit  3031  controls a heuristic verification process that uses the statistical processing carried out by the first verification unit  3009  and functions in cooperation with various processing units of the first verification unit  3009 . 
     The operation judging unit  3033  is realized by a CPU, a ROM, a RAM, and the like, for example. The operation judging unit  3033  inputs various information such as sensor information and execution command information acquired from the power management apparatus  11  to be verified and judges whether the operation of the power management apparatus  11  being verified is normal or abnormal based on history information and the like of the power management apparatus  11  or another power management apparatus  11 . The judging process carried out by the operation judging unit  3033  will be described later. 
     The database management unit  3035  is realized by a CPU, a ROM, a RAM, and the like, for example. The database management unit  3035  stores various information such as sensor information of new batteries and appliances, execution command information, and history information that have been transmitted from the power management apparatus  11  in the database  3041  and also updates the judging dictionary  3043 . The database management unit  3035  regularly compares statistics of a specified power management apparatus  11  and statistics in data of other power management apparatuses  11  and tests whether there is data that has been deliberately generated. 
     The virus definition file management unit  3037  is realized by a CPU, a ROM, a RAM, and the like, for example. The virus definition file management unit  3037  defines execution command information which the operation judging unit  3033  has judged to be abnormal as a virus pattern and generates a virus definition file. The virus definition file management unit  3037  stores the generated virus definition file in the virus definition file database  3045  to update the database, and also transmits the generated virus definition file via the verification control unit  3031  to the outside. 
     The shared information generating unit  3039  gathers information (for example, sensor information on batteries/appliances, execution command information, appliance information on batteries/appliances, usage history information, and the like) on a power management apparatus  11  that has been detected as being abnormal by the operation judging unit  3033  as shared information. After this, the shared information generating unit  3039  outputs the generated shared information via the verification control unit  3031  and the acquired data verification control unit  3007  to the second verification unit  3011 . 
     By using the shared information to update the setting information (parameters and the like) for a simulation, the second verification unit  3011  is capable of further improving the simulation precision. 
     The power management apparatus database  3041  is one example of a database stored in the first verification unit  3009 . Various information such as appliance information relating to the batteries and appliances, usage environment information, and usage history information of each power management apparatus  11  is stored in this database. 
     The judging dictionary  3043  is another database stored in the first verification unit  3009  and stores information relating to characterizing amounts when the operation judging unit  3033  heuristically judges operations. Such characterizing amounts are statistics on typical sensor information when certain conditions (appliance information, usage environment information, and the like) are provided and are generated based on the power management apparatus database  3041 . 
     The virus definition file database  3045  is yet another database stored in the first verification unit  3009 . The virus definition file database  3045  stores virus definition files generated by the virus definition file management unit  3037 . 
     This completes the detailed description of the configuration of the first verification unit  3009 . 
     Configuration of Second Verification Unit 
     Next, the configuration of the second verification unit  3011  will be described in detail with reference to  FIG. 62 . 
     As described above, the second verification unit  3011  calculates a normal operating range by carrying out a simulation based on changes over time and usage environment, usage history, usage state, and characteristic information of a battery, and detects differences and abnormalities at high speed. The verification by the first verification unit  3009  is a high-speed determination method that uses statistical information from a virtual environment or the like, but the verification by the second verification unit  3011  is time consuming. However, the second verification unit  3011  is possible to calculate deterioration in the quality of a genuine product with high precision. 
     The second verification unit  3011  includes a function that uses shared information outputted from the first verification unit  3009  to update various setting information (parameters) to be used when carrying out simulation to appropriate values. 
     As shown in  FIG. 62 , the second verification unit  3011  further includes an estimated characteristic value calculating unit  3051 , a database  3053 , and a data judging unit  3055 . 
     The estimated characteristic value calculating unit  3051  is realized by a CPU, a ROM, a RAM, and the like, for example. The estimated characteristic value calculating unit  3051  carries out a simulation based on the appliance information, electric specification and characteristic information, and usage history information acquired from the power management apparatus  11  to be verified to calculate estimated characteristic values. The estimated characteristic values are indices (that is, a normal operating range) showing whether an appliance is operating appropriately. When carrying out the simulation, the estimated characteristic value calculating unit  3051  acquires various parameters for the simulation that are registered in the database  3053 . 
     The database  3053  is a database stored in the second verification unit  3011  and stores various setting information (parameters) used when the estimated characteristic value calculating unit  3051  carries out simulation. As described above, the parameters stored in the database  3053  are updated by the second verification unit  3011  using shared information outputted from the first verification unit  3009 . 
     The data judging unit  3055  is realized by a CPU, a ROM, a RAM, and the like, for example. The data judging unit  3055  compares the various data acquired from the power management apparatus  11  to be verified and the estimated characteristic values calculated by the estimated characteristic value calculating unit  3051  and judges the various data acquired from the power management apparatus  11  to be verified. By using arbitrary logic, the data judging unit  3055  is capable of detecting an abnormality at a battery/appliance or sensor, and as one example, when a discrepancy between an actual value and an estimated characteristic value is equal to or above a specified threshold or when the discrepancy is equal to or below the threshold, the data judging unit  3055  can judge that an abnormality has occurred at the appliance. 
     In the second verification unit  3011 , the parameters used in a physical simulation can be corrected to more realistic values. It is also possible to transmit such information to a battery or appliance manufacturer to inform the manufacturer of failures that were not imagined in advance. 
     This completes the detailed description of the configuration of the second verification unit  3011 . 
     One example of the functions of the analysis server  34  according to the present embodiment has been described above. The component elements described above may be constructed using general-purpose parts and/or circuits or may be constructed by hardware that is dedicated to the functions of the respective component elements. Alternatively, the functions of the respective component elements may all be carried out by a CPU or the like. Accordingly, it is possible to change the configuration in use as appropriate in accordance with the prevailing technical level when implementing the present embodiment. 
     Note that a computer program for realizing the functions of the analysis server according to the present embodiment described above may be created and installed in a personal computer or the like. It is also possible to provide a computer-readable recording medium on which such a computer program is stored. As examples, the recording medium may be a magnetic disk, an optical disc, a magneto-optical disc, a flash memory, or the like. The computer program mentioned above may also be distributed via a network, for example, without using a recording medium. 
     (1-21) Process Specifying Battery to be Excluded 
     Next, the process for specifying a battery to be excluded that is carried out by the analysis server  34  with the functions described above will be described with reference to  FIG. 63 .  FIG. 63  is a diagram useful in explaining batteries to be excluded. 
     The table shown in  FIG. 63  is a list of conceivable states for a battery used in the local power management system  1 . As shown at the top of  FIG. 63 , the battery used in the local power management system  1  includes one or a plurality of cells that store power, a circuit board for controlling the cell or cells, and an authentication chip provided on the circuit board. The conceivable states for the cells and the circuit board including the authentication chip can be roughly classified into the seven cases shown in the table. 
     Case 1 to case 3 are states that may occur in a battery composed of genuine cells and a genuine circuit board. Case 4 to case 7 are states that may occur in a battery that uses fake cells. 
     Out of the seven cases, there are no problems with the cell characteristics in case 1, case 2, and case 4 and a correct appliance state is being outputted. Since batteries classified into such cases have either deteriorated within an estimated range or are copies which have characteristics or information that are not problematic, such batteries do not pose a major problem if present in a local power management system. 
     However, for batteries classified into case 3 and cases 5 to 7, a discrepancy is produced when the characteristics or appliance information of cells are compared to a case with genuine products in normal use, and since such products present various kinds of risk, it is necessary to excluded such batteries from the local power management system  1 . 
     For this reason, by using various verification processes as described above, the analysis server  34  according to the present embodiment is capable of specifying the batteries mentioned above that should be excluded. 
     The process for specifying batteries to be excluded which is carried out by the analysis server  34  will be described in detail later. 
     (1-22) Method of Protecting Against Illegal Attacks to Power Management Apparatus 
     Next, the overall flow of a method of protecting against illegal attacks to a power management apparatus will be described with reference to  FIG. 64 .  FIG. 64  is a flowchart useful in explaining a method of protecting against illegal attacks to the power management apparatus. 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has been set so as to subscribe to a service that prevents illegal attacks (that is, a service provided by the analysis server  34 ) and the execution frequency, timing, and the like of such service have been set in advance. 
     The system management unit  1125  of the power management apparatus  11  first judges whether timing for checking the presence of illegal attacks has been reached (step S 3001 ). If the check timing has not been reached, the system management unit  1125  of the power management apparatus  11  awaits the check timing to be reached. If the check timing has been reached, the system management unit  1125  of the power management apparatus  11  uses attack pattern files (virus definition files) stored thusfar in the power management apparatus  11  to search the system (step S 3003 ). 
     When there is a problem in a pattern check, the system management unit  1125  of the power management apparatus  11  registers the problematic appliance in an appliance exclusion list stored in the power management apparatus  11  and the control unit  115  excludes the problematic appliance from the system (step S 3005 ). 
     If there are no problems in the pattern check, the appliance management unit  1121  of the power management apparatus  11  gathers various information such as sensor information and execution command information from the various appliances including batteries that are connected to the system (step S 3007 ). After this, the appliance management unit  1121  of the power management apparatus  11  accesses the analysis server  34  via mutual authentication (step S 3009 ). When a connection has been established, the power management apparatus  11  encrypts the ID of the power management apparatus, the battery ID of each appliance, output information of the batteries, sensor information and execution command information of the power management apparatus and transmits the encrypted information to the analysis server  34  (step S 3011 ). 
     The acquired data verification unit  3005  of the analysis server  34  determines whether there are any abnormalities in various data transmitted from the power management apparatus  11  (step S 3013 ). When there are no abnormalities, the acquired data verification unit  3005  adds the acquired data on the power management apparatus  11  to the database (step S 3015 ) and informs the power management apparatus  11  of the analysis result (step S 3017 ). 
     Meanwhile, when an abnormality has been identified in step S 3013 , the acquired data verification unit  3005  of the analysis server  34  generates a virus definition file (step S 3019 ). The acquired data verification unit  3005  of the analysis server  34  checks whether many abnormalities have occurred at the power management apparatus  11  where the abnormality was identified (step S 3021 ). When it has been judged that many abnormalities have occurred and that the power management apparatus  11  has become a launchpad for attacks or the like, the analysis server  34  informs the system management server  33  of an abnormality (step S 3023 ). The system management server  33  that has received the report excludes the apparatus in question by placing the apparatus on a blacklist, for example (step S 3025 ). The analysis server  34  also transmits the analysis result and the virus definition file generated in step S 3019  to the power management apparatus  11  (step S 3027 ). The system management unit  1125  of the power management apparatus  11  receives the result and carries out appropriate processing such as updating the virus definition file when one exists (step S 3029 ). 
     This completes the description of the overall flow of the method of protecting against illegal attacks to a power management apparatus. 
     (1-23) Method of Excluding Battery 
     Next, the flow of a process carried out by the analysis server  34  to specify a battery to be excluded and a process carried out by the power management apparatus  11  to exclude such battery will be described with reference to  FIG. 65 .  FIG. 65  is a flowchart useful in explaining the method of excluding a battery. 
     The analysis server  34  according to the present embodiment detects whether an abnormality is present at a battery based on the information transmitted from the power management apparatus  11  and informs the power management apparatus  11  when an abnormality has occurred. The power management apparatus  11  that has been informed of the abnormality carries out a series of operations, such as stopping the supplying of power to the abnormal battery. 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has been set so as to subscribe to a service that excludes battery risks (that is, a service provided by the analysis server  34 ) and the execution frequency, timing, and the like of such service are set in advance. 
     The system management unit  1125  of the power management apparatus  11  first judges whether timing for checking for battery risks has been reached (step S 3031 ). If the check timing has not been reached, the system management unit  1125  of the power management apparatus  11  awaits the check timing to be reached. If the check timing has been reached, the appliance management unit  1121  of the power management apparatus  11  requests the control-compliant appliances  125  and the like that include a battery to transmit battery information (battery primary information). In response, the respective control-compliant appliances  125  that include batteries transmit battery information to the power management apparatus  11  (step S 3033 ). The power management apparatus  11  checks whether battery information has been acquired from every appliance (step S 3035 ). Note that although it is not absolutely necessary to acquire battery information from every appliance, it is preferable to check all of the appliances. 
     The appliance management unit  1121  of the power management apparatus  11  accesses the analysis server  34  via mutual authentication (step S 3037 ). When a connection has been established, the power management apparatus  11  transmits the ID of the power management apparatus, the battery ID of each appliance, and primary information of the batteries to the analysis server  34  (step S 3039 ). 
     The acquired data verification unit  3005  of the analysis server  34  calculates estimated characteristic values using the various data transmitted from the power management apparatus  11  and compares the acquired data with the calculated estimated characteristic values. After doing so, the acquired data verification unit  3005  of the analysis server  34  informs the obtained results to the power management apparatus  11  (step S 3041 ). 
     The system management unit  1125  of the power management apparatus  11  judges the obtained result (step S 3043 ). When the result is that there are no abnormalities, the appliance management unit  1121  of the power management apparatus  11  checks the physical information gathered from the sensors (step S 3045 ) and ends the processing if there are no problems. 
     When there is an abnormality in step S 3043 , the control unit  115  of the power management apparatus  11  issues a power supplying stop command for the appliance with the battery with the abnormality to the power distribution apparatus  121  (step S 3047 ). The power distribution apparatus  121  stops the supplying of power to such appliance in accordance with the command from the power management apparatus  11  (step S 3049 ). The system management unit  1125  of the power management apparatus  11  places the ID of the appliance with the abnormality on a revoke list and the appliance management unit  1121  disconnects the information network of the appliance (step S 3051 ). 
     By carrying out the processing described above, the analysis server  34  is capable of specifying a battery to be excluded and the power management apparatus  11  is capable of excluding such battery to be excluded from the system. 
     (1-24) Verification Process by Acquired Data Verification Unit 
     Next, the overall flow of a verification process by the acquired data verification unit  3005  of the analysis server  34  will be described with reference to  FIGS. 66A and 66B .  FIGS. 66A and 66B  are flowcharts useful in explaining the verification process by the acquired data verification unit. 
     The acquired data verification control unit  3007  of the acquired data verification unit  3005  of the analysis server  34  first acquires various data transmitted from the power management apparatus  11  (step S 3061 ). Next, the acquired data verification control unit  3007  tests the acquired data using a predetermined filter (step S 3063 ). As examples, the filter may protect against a DoS attack where a large amount of information is transmitted from a specified power management apparatus  11 , may function as a firewall, and/or may reject nonstandard communication. 
     If an abnormality is detected in the filter processing on the acquired data, the acquired data verification control unit  3007  outputs an abnormality judgment (step S 3083 ), implements a specified warning process (step S 3085 ), and ends the flow. As one example, the warning process may be carried out for the system management server  33  or another server that is related to the power management apparatus in question. 
     Meanwhile, if an abnormality is not detected in the filter processing on the acquired data, the acquired data verification control unit  3007  implements a simplified judging process on the acquired data (step S 3065 ). The simplified determination is assumed to include detecting virus patterns understood in advance by the analysis server  34 , carrying out a simplified judgment by the first verification unit  3009 , and/or carrying out matching against typical usage, with such processing normally being carried out at high speed. When it is possible at this stage to clearly confirm that the operation is normal, a normal judgment is outputted (step S 3081 ) and the flow ends. 
     Meanwhile, if this simplified judgment has judged that an abnormality is present or if judgment was not possible, the acquired data verification control unit  3007  judges which of three judgment processes which are numbered pattern 1 to pattern 3 and described below is to be used (step S 3067 ). 
     Pattern 1 is a pattern that selects a linked judging process that uses a combination of the first verification unit  3009  and the second verification unit  3011 . 
     For example, the acquired data verification control unit  3007  first carries out a judgment via statistical processing by the first verification unit  3009  (step S 3069 ) and also grasps the physical characteristics of a battery/appliance from the transmitted information. Here, the acquired data verification control unit  3007  judges the processing path (step S 3071 ) and judges whether to output the final results (step S 3075 ) or carry out verification by the second verification unit  3011  (step S 3073 ). When verification by the second verification unit  3011  is also carried out, the second verification unit  3011  updates the physical parameters used in the simulation based on the shared information (that is, physical characteristics) received from the first verification unit  3009  and carries out simulation based on the transmitted information. In addition, the first verification unit  3009  updates the judging dictionary based on findings obtained by the verification by the second verification unit  3011  and carries out judgment again based on statistical processing. 
     It is also possible to select a judgment process where a point that should be investigated in more detail is clearly established in a judgment by one of the verification units and this is then fed back into a judgment by the other verification unit. In this way, pattern 1 is a method that improves the judgment precision through complimentary use of the first verification unit  3009  and the second verification unit  3011 . 
     Pattern 2 is a pattern that selects a linear judgment process where verification by the first verification unit  3009  and verification by the second verification unit  3011  are carried out in that order. 
     More specifically, the acquired data verification control unit  3007  first implements verification using the first verification unit  3009  that is capable of judgment in a comparatively short processing time (step S 3077 ) and, if the judgment result is not normal, then switches to verification by the second verification unit  3011  that takes a longer processing time (step S 3079 ). Here, it is assumed that verification by the first verification unit  3009  is a more detailed investigation than verification in the simplified judgment. 
     When pattern 2 is used, if a judgment of “normal” is produced by the verification by the first verification unit  3009 , the acquired data verification control unit  3007  outputs a normal judgment (step S 3081 ) and the flow ends. 
     In  FIG. 66A , a case is assumed where verification by the first verification unit  3009  that is comparatively fast is implemented first, but it is also possible to implement verification by the second verification unit  3011  first. 
     Pattern 3 is a pattern that selects a parallel judgment process where verification by the first verification unit  3009  and verification by the second verification unit  3011  are used simultaneously. 
     The acquired data verification control unit  3007  decides whether to carry out verification by both the first verification unit  3009  and the second verification unit  3011  or to carry out verification using only one of such verification units, as well as what attributes to investigate (step S 3087 ). The first verification unit  3009  (step S 3089 ) and the second verification unit  3011  (step S 3091 ) carry out respective investigations, and the acquired data verification control unit  3007  carries out a final judgment based on the investigation results from both processing units (step S 3093 ). 
     Note that although it is possible to carry out one of the three methods (patterns) described above, it is also possible to carry out the three methods in parallel. It is also possible to adaptively allocate such methods according to the range or the like of attribute information and/or the sensor information to be investigated. It would also be possible to produce a potentially high-speed model by using a plurality of patterns 1 to 3 in parallel instead of just pattern 1 to pattern 3 individually. 
     (1-25) Flow of Verification Process by First Verification Unit 
     Next, the flow of a verification process by the first verification unit will be described with reference to  FIG. 67 .  FIG. 67  is a flowchart useful in explaining the verification process by the first verification unit. 
     The verification control unit  3031  of the first verification unit  3009  first acquires at least one of battery/sensor information and execution command information for the power management apparatus  11  to be verified as the verification data (step S 3101 ). Next, the operation judging unit  3033  carries out preprocessing that shapes a data format of the acquired information (for example, sensor information of a battery or appliance) (step S 3103 ). 
     After this, the operation judging unit  3033  designates specified attribute information (for example, appliance information, usage environment information) and, in accordance with the attributes, extracts characterizing amounts from data (sensor information of a battery or appliance, execution command information) that has been shaped by the preprocessing (step S 3105 ). Since typical characterizing amounts for the attribute information designated when characterizing amounts are extracted are calculated in advance from usage history of the power management apparatus to be verified or another power management apparatus, typical characterizing amounts for the designated attribute information will have been stored in the judgment dictionary. 
     Note that the characterizing amounts are as follows.
         characteristic amounts given by battery/sensor information and usage history of a power management apparatus that is not being verified.   characteristic amounts given by battery/sensor information/history of the power management apparatus being verified   characteristics of execution commands of a power management apparatus not being verified   characteristics of execution commands of the power management apparatus being verified       

     Next, the first operation judging unit  3033  compares a typical characterizing amount for the designated attribute information and the calculated characterizing amount (step S 3107 ) and outputs a judgment result (step S 3109 ). As one example, the operation judging unit  3033  can judge that an abnormality has occurred when the degree of correlation between the two characterizing amounts is low, and can judge that a state is normal when the degree of correlation is high. 
     Another operation judging unit  3033  may also carry out the same processing for the same characterizing amount or a different characterizing amount (step S 3111  to step S 3115 ) and output a judgment result. 
     After this, the verification control unit  3031  may give a final judgment of normal/abnormal based on judgment results from every operation judging unit  3033  (step S 3117 ). For example, the verification control unit  3031  may give a majority judgment when judgments of normal/abnormal have been given by every operation judging unit  3033 . Alternatively, the verification control unit  3031  may use a method where a sum is calculated using a weighting of 1 for normal and 0 for abnormal and a final judgment of normal is given when the sum is equal to or above a threshold. When calculating the degree of correlation or value of a function, the verification control unit  3031  may find a sum having applied the same weightings as above and then judge using a threshold or use some type of function. 
     The verification control unit  3031  outputs an overall judgment result obtained as described above to the acquired data verification control unit  3007  (step S 3119 ) and ends the verification process. The acquired data verification control unit  3007  outputs the obtained verification result to a power management apparatus, the user himself/herself, and a server or the like that provides other services. 
     Note that as examples, the operation judging unit  3033  may use a method such as a nearest neighbor rule, a perceptron, a neural network, a support vector machine, multivariate analysis, or boosting as the judging function. The parameters of the judging function can be determined by learning in advance based on data on another power management apparatus  11  and/or physical data. 
     Note that if an abnormality has been ultimately identified by the process described above, the virus definition file management unit  3037  extracts a pattern from the execution command information for which the abnormality was identified and generates a virus definition file. 
     (1-26) Testing Process by Database Management Unit 
     Next, a testing process for a database management unit  3035  of the first verification unit  3009  will be described with reference to  FIG. 68 .  FIG. 68  is a flowchart useful in explaining the testing process by the database management unit. 
     In the database management unit  3035 , statistics on data acquired from a specified power management apparatus  11  are regularly compared with statistics on data acquired from another power management apparatus and tests are carried out into whether data that has been deliberately generated is present. 
     To detect abnormal operations by the operation judging unit  3033 , the database management unit  3035  normally extracts characterizing amounts for comparison purposes in advance from various information (for example, sensor information of a battery or appliance) gathered from many power management apparatuses. 
     Here, there is the risk of a malicious power management apparatus  11  transmitting sensor information and the like of a battery or appliance that has been tampered with to manipulate the characterizing amounts. For this reason, by comparing characterizing amounts extracted from usage history information of a specified power management apparatus that has specified attribute information (for example, appliance information and usage environment information) and characterizing amounts extracted from usage history of a plurality of other power management apparatuses with the same attribute information, the virus definition file management unit  3037  detects such an attack. 
     First, regarding specified attribute information, the database management unit  3035  first obtains sensor information or execution command information of a power management apparatus which is to be judged as malicious or normal (step S 3121 ), and extracts characterizing amounts from the acquired information (step S 3123 ). The database management unit  3035  acquires the same information from a plurality of other power management apparatuses that have the same attribute information (step S 3125 ), and extracts characterizing amounts using the same method (step S 3127 ). 
     Next, the database management unit  3035  compares the two characteristic amounts that have been extracted and judges whether the specified power management apparatus currently subject to attention is illegally manipulating the characteristic amounts (step S 3129 ) and outputs a final result (step S 3131 ). Alternatively, the database management unit  3035  may carry out the same comparison and judgment for other attributes and then decide the final result. Note that one of the judging functions listed earlier is used for the comparison and judgment of characterizing amounts, with the parameters for such function being calculated in advance by learning. 
     When the judgment result is that a power management apparatus is malicious, the analysis server  34  informs the user who owns the power management apparatus  11  and/or a service providing server of a power company or the like. 
     (1-27) Updating of Database and Generation of Judgment Dictionary 
     Next, updating of the database and generation of the judgment dictionary by the database management unit  3035  will be described in brief with reference to  FIG. 69 .  FIG. 69  is a diagram useful in explaining updating of the database and generation of the judgment dictionary by the database management unit. 
     The database management unit  3035  stores new sensor information and execution command information or the like from the power management apparatus  11  in the power management apparatus database  3041  and also generates the judging dictionary  3043  used by the operation judging unit  3033 . 
     The sensor information and execution command information that are regularly transmitted from the power management apparatus  11  and the appliance information, usage environment information and the like transmitted from the power management apparatus  11  during registration are stored in the power management apparatus database  3041  via the verification control unit  3031 . The usage time, usage frequency and the like of a specified power management apparatus  11  are also calculated based on sensor information and are stored in the power management apparatus database  3041 . 
     For respective attributes out of specified attribute information, characterizing amounts extracted based on sensor information, execution command information, and the like of a plurality of power management apparatuses  11  are stored in the judging dictionary  3043  used by the operation judging unit  3033 . Since it is imagined that few samples will be stored in the judging dictionary  3043  at an initial stage, physical data relating to respective appliances is transmitted from the power management apparatus  11  and characteristic amounts are estimated. Also, since the number of samples may be low for specified attribute information, in some cases characteristic amounts may be extracted from the physical data and used to correct the characterizing amounts stored in the judging dictionary  3043 . 
     (1-28) Method of Managing Virus Definition File 
     Next, the method of managing a virus definition file carried out by the virus definition file management unit  3037  will be described in brief with reference to  FIG. 70 .  FIG. 70  is a flowchart useful in explaining a method of managing a virus definition file carried out by the virus definition file management unit. 
     The virus definition file management unit  3037  defines execution command information, which has been judged to be abnormal in a judgment by the operation judging unit  3033 , as a virus pattern to generate a virus definition file. After this, the virus definition file management unit  3037  stores the generated virus definition file in the virus definition file database  3045 . 
     Before generating a virus definition file, first, the operation judging unit  3033  judges that the operation of a certain power management apparatus  11  is abnormal (step S 3141 ). After this, the virus definition file management unit  3037  analyzes the execution command information judged to be abnormal by the operation judging unit  3033  and extracts a pattern (step S 3143 ). 
     Next, the virus definition file management unit  3037  generates a file (virus definition file) based on the extracted pattern (step S 3145 ) and stores the generated definition file in the virus definition file database  3045 . The virus definition file management unit  3037  transmits the generated definition file via the acquired data verification control unit  3007  to the power management apparatus  11  (step S 3149 ). Each power management apparatus  11  and the analysis server  34  are capable of using this definition file as a filter for detecting viruses. 
     The virus definition file management unit  3037  analyzes the usage history information of the power management apparatus  11  including the execution command information from which the pattern was extracted. As a result, if abnormalities are frequently produced from the power management apparatus  11 , in some cases the power management apparatus  11  is regarded as a malicious attacker and is registered on a blacklist (step S 3151 ). The virus definition file management unit  3037  may also report the presence of such power management apparatus  11  to a power company. 
     Note that when a power management apparatus is registered on the blacklist, the reception of communication from the registered power management apparatus is denied and/or other power management apparatuses are warned. 
     (1-29) Flow of Method of Specifying Battery to be Excluded 
     Next, the flow of a method implemented by the acquired data verification unit  3005  to specify a battery to be excluded will be described with reference to  FIGS. 71A to 72 .  FIGS. 71A to 72  are flowcharts useful in explaining a method implemented by the acquired data verification unit to specify a battery to be excluded. 
     First, a process that specifies batteries that correspond to case 3, case 5, and case 6 in  FIG. 63  will be described with reference to  FIGS. 71A to 71C . 
     Note that it is assumed that before the following explanation begins, the power management apparatus  11  has been set so as to subscribe to a service that excludes battery risks (that is, a service provided by the analysis server  34 ) and the execution frequency, timing, and the like of such service is set in advance (step S 3161 ). 
     If the timing for checking for battery risks has been reached, the system management unit  1125  of the power management apparatus  11  requests a control-compliant appliance  125  that is a managed appliance managed by the power management apparatus  11  to carry out a performance check (step S 3163 ). 
     A main part of the control-compliant appliance  125  then requests a battery connected thereto to acquire temporary-state information (that is, cell characteristics) D 1  relating to voltage/current/remaining charge/impedance/load and the like relating to the battery and appliance information D 2  (step S 3165 ). 
     The battery connected to the control-compliant appliance  125  acquires the information D 1  and D 2  (step S 3167 ) and transmits such information and ID information of the battery via the main part of the control-compliant appliance  125  to the power management apparatus  11  (step S 3169 ). 
     The appliance management unit  1121  of the power management apparatus  11  stores the acquired information in a database stored in the power management apparatus  11  (step S 3171 ). The power management apparatus  11  also makes a specific enquiry to the analysis server  34  (step S 3173 ). After this, the power management apparatus  11  carries out authentication with the analysis server  34  (step S 3175 ) and establishes a communication path with the analysis server  34 . 
     Next, the system management unit  1125  of the power management apparatus  11  transmits the acquired information (D 1 , D 2 , and ID information of the battery) to the analysis server  34  (step S 3177 ). 
     The second verification unit  3011  of the acquired data verification unit  3005  in the analysis server  34  uses the acquired data to carry out a characteristic estimation calculation (step S 3179 ) to calculate estimated characteristic values relating to the information D 1  and D 2 . After this, the second verification unit  3011  calculates discrepancies between the actual measurements and the estimated values and judges the result (step S 3181 ). Next, the analysis server  34  transmits the obtained judgment result to the power management apparatus  11  (step S 3183 ). 
     Here, the judgment results obtained in step S 3181  are expected to be as follows for the respective cases. 
     (Case 3) 
     Discrepancy for D 1 : Outside Specified Range, Discrepancy for D 2 : Outside Specified Range 
     (Case 5) 
     Discrepancy for D 1 : Outside Specified Range, Discrepancy for D 2 : Outside Specified Range 
     (Case 6) 
     Discrepancy for D 1 : Outside Specified Range, Discrepancy for D 2 : Outside Specified Range 
     The power management apparatus  11  that has acquired such judgment result carries out processing for handling the abnormality (step S 3185 ). More specifically, the appliance management unit  1121  of the power management apparatus  11  commands the power distribution apparatus  121  to stop supplying power to the control-compliant appliance  125  where the abnormality has occurred (step S 3187 ). The power distribution apparatus  121  receives the command and stops the supplying of power to the control-compliant appliance  125  (step S 3189 ). 
     Meanwhile, the system management unit  1125  of the power management apparatus  11  issues a warning to the user (step S 3191 ) and updates a revoke list (step S 3193 ). After this, the power management apparatus  11  disconnects the network of the control-compliant appliance  125  in question (step S 3195 ). 
     Note that although a process where the analysis server  34  specifies a battery to be excluded is shown in  FIG. 71A , if the power management apparatus  11  has a function for calculating the estimated characteristic values, the process shown in  FIG. 71C  may be carried out in place of steps S 3177  to S 3183  in  FIG. 71A . More specifically, the power management apparatus  11  requests information, such as characteristic values, that is necessary to calculate the estimated characteristic values from the analysis server  34  (step S 3201 ). On receiving such request, the analysis server  34  transmits the information necessary to calculate the estimated characteristic values to the power management apparatus  11  (step S 3203 ). After this, the power management apparatus  11  uses the acquired information to calculate the estimated characteristic values (step S 3205 ) and judges the result (step S 3207 ). By carrying out processing in this way, it is possible for the power management apparatus  11  also to specify batteries to be excluded. 
     Next, the flow for specifying and excluding batteries that correspond to case 7 will be described with reference to  FIG. 72 . The processing up to the specifying of batteries that correspond to case 7 is the same as steps S 3161  to S 3183  shown in  FIG. 71A . However, the judging result for batteries that correspond to case 7 is as follows. 
     (Case 7) 
     Discrepancy for D 1 : Outside Specified Range, Discrepancy for D 2 : Within Specified Range 
     The power management apparatus  11  that has acquired the above judging result carries out processing to handle the abnormality (step S 3211 ). More specifically, the appliance management unit  1121  of the power management apparatus  11  transmits a sensor check command and a command that increases the check frequency to the control-compliant appliance  125  (step S 3213 ). On receiving such a command, the control-compliant appliance  125  implements the received command and requests the sensor to carry out measurement (step S 3215 ). As a result, the sensor outputs sensor information relating to a warning (step S 3217 ). 
     The power management apparatus  11  that has acquired the sensor information relating to a warning commands the power distribution apparatus  121  to stop supplying power to the control-compliant appliance  125  where the abnormality occurred (step S 3219 ). The power distribution apparatus  121  receives the command and stops supplying power to the control-compliant appliance  125  (step S 3221 ). 
     Meanwhile, the system management unit  1125  of the power management apparatus  11  issues a warning to the user (step S 3223 ) and updates the revoke list (step S 3225 ). After this, the power management apparatus  11  disconnects the network of the control-compliant appliance  125  in question (step S 3227 ). 
     This completes the description of the flow of the method of specifying batteries to be excluded and the method of excluding batteries. 
     Due to the presence of the analysis server  34  described above, it is possible to protect the power management apparatus  11  not only from existing attacks but also from unknown attacks. The acquired data verification unit  3005  of the analysis server  34  according to the present embodiment has a function that is capable of judgments that are heuristic or based on physical analysis, which means that judging can be carried out at high speed when a problem has not occurred. 
     Also, by using verification results produced by the acquired data verification unit  3005 , it is possible to specify appliances where a discrepancy has been identified for physical information or digital information obtained from any of a legitimate battery and an illegal battery such as a copy. By doing so, it is possible to remove a problematic battery from the local power management system  1  or to stop supplying power to such battery. Various safety measures are enacted for batteries, but even when control is not possible via such safety measures, it is possible via the present method to ensure that safety is maintained. 
     (1-30) Processing when Multiple Power Management Apparatuses are Present 
     Next, the processing when a plurality of power management apparatuses  11  are present in the local power management system  1  will be described with reference to  FIGS. 73 to 75 . 
     Here, use of multiple power management apparatuses  11  will be described with reference to  FIGS. 73 to 75 . As described above, a power management apparatus  11  acts as an overall manager over the supplying of power to appliances and the like in the local power management system  1 . This means that if the power management apparatus  11  fails or stops due to a software update, it becomes no longer possible to use the appliances and the like in the local power management system  1 . In readiness for such situation, it is preferable to use multiple power management apparatuses  11 . However, a power management apparatus  11  acts as an overall manager for information relating to power and controls the various appliances and the like in the local power management system  1 . This means that certain measures are wanted to cause a plurality of power management apparatuses  11  to safely and efficiently carry out complex management and control. One conceivable measure is the method shown in  FIGS. 73 to 75 . 
     Control Operation 
     First, a method of controlling the appliances and the like using multiple power management apparatuses  11  will be described with reference to  FIG. 73 . Note that cooperative operation by a plurality of power management apparatuses  11  is realized by the functions of the system management unit  1125  included in the information management unit  112 . 
     As shown in  FIG. 73 , first, the system management unit  1125  checks whether two or more power management apparatuses  11  are operating (step S 4001 ). When doing so, the system management unit  1125  uses the functions of the local communication unit  111  to enquire to the system management units  1125  of other power management apparatuses  11  and check whether such power management apparatuses  11  are operating. When two or more power management apparatuses  11  are operating, the processing of the system management unit  1125  proceeds to step S 4003 . Meanwhile, when no other power management apparatuses  11  are operating, the processing of the system management unit  1125  proceeds to step S 4009 . 
     When the processing has proceeded to step S 4003  from step S 4001 , the system management unit  1125  sets a specified power management apparatus  11  as a parent device and sets the remaining power management apparatuses  11  as child devices (step S 4003 ). For example, when a priority-based order for setting power management apparatuses as the parent device has been decided in advance, the power management apparatus  11  with the highest priority ranking is set as the parent device. Note that the expressions “parent device” and “child device” used here refer to an attribute of a power management apparatus  11 . By setting this attribute, a power management apparatus  11  with a “child device” attribute transmits a control signal to a power management apparatus  11  with a “parent device” attribute when controlling an appliance or the like (step S 4005 ). 
     When control signals have been transmitted from a plurality of child devices to the parent device, the system management unit  1125  of the parent device decides the control signal to be transmitted to an appliance or the like based on a majority decision or a judgment by the parent device (randomly or according to a predetermined condition) (step S 4007 ). Once the control signal has been decided, the control unit  115  transmits the control signal decided by the system management unit  1125  to the appliance or the like to cause the appliance or the like to carry out processing according to the control signal (step S 4011 ) and ends the series of processes. Meanwhile, when the processing has proceeded to step S 4009  from step S 4001 , the control unit  115  transmits a self-created control signal to the appliance or the like to cause the appliance or the like to carry out processing according to the control signal (step S 4009 ) and ends the series of processes. 
     In this way, the system management unit  1125  has a function for setting the attribute of each power management apparatus  11  and a function for selecting a control signal. The system management unit  1125  is capable of efficiently controlling appliances and the like using such functions. It is also possible, when one or more power management apparatuses  11  have broken down or have stopped for updating purposes, to have another power management apparatus  11  continue power management and thereby avoid a situation where appliances and the like become unusable. 
     Operation During Updating 
     Next, a method of updating the software (or “firmware”) that defines the fundamental operation of the power management apparatus  11  will be described with reference to  FIGS. 74 and 75 . Note that the updating process for the firmware is realized by a function of the system management unit  1125 . Here, it is assumed that N power management apparatuses  11  are operating within the local power management system  1 . 
     As shown in  FIG. 74 , the system management unit  1125  first checks whether two or more power management apparatuses  11  are operating (step S 4021 ). When two or more power management apparatuses  11  are operating, the processing of the system management unit  1125  proceeds to step S 4023 . Meanwhile, when no other power management apparatus  11  is operating, the system management unit  1125  ends the series of processes relating to updating. 
     When processing has proceeded to step S 4023 , the system management unit  1125  removes the first power management apparatus  11  to be updated from the cooperative operation and carries out updating (step S 4023 ). When doing so, the system management unit  1125  of the power management apparatus  11  that has been removed from the cooperative operation acquires the latest firmware from the system management server  33  and updates the old firmware to the latest firmware. When the updating of the firmware has been completed, the remaining power management apparatuses  11  that are operating cooperatively check the operation of the power management apparatus  11  whose updating has been completed (steps S 4025 , S 4027 ). 
     If the power management apparatus  11  is operating normally, the processing proceeds to step S 4029 . Meanwhile, if the updated power management apparatus  11  is not operating normally, the processing proceeds to step S 4031 . When the processing has proceeded to step S 4029 , the system management units  1125  of the plurality of power management apparatuses  11  that include the updated power management apparatus  11  return the updated power management apparatus  11  to the cooperative operation (step S 4029 ), and change the power management apparatus  11  to be updated. At this time, it is checked whether the updating has been completed for all N power management apparatuses  11  (step S 4033 ), and when the updating of N apparatuses is complete, the updating process ends. 
     Meanwhile, when the updating has not been completed for all N power management apparatuses  11 , the processing returns to step S 4023  and the updating process is carried out on the next power management apparatus  11  to be updated. In this way, the processing in steps S 4023  to S 4029  is repeatedly executed until the updating of all N power management apparatuses  11  has been completed. However, when the processing has proceeded from step S 4027  to step S 4031 , an updating cancelling process is carried out (step S 4031 ), and the series of processes relating to updating is completed. 
     Here, the updating cancelling process will be described with reference to  FIG. 75 . 
     As shown in  FIG. 75 , when the updating cancelling process is commenced, the system management unit  1125  of the updated power management apparatus  11  returns the firmware of the updated power management apparatus  11  to the state before updating (step S 4041 ). After this, the system management units  1125  of the remaining power management apparatuses  11  that are operating cooperatively check whether the power management apparatus  11  that has been returned to the state before updating is operating normally (steps S 4043 , S 4045 ). 
     If the power management apparatus  11  that has been returned to the state before updating is operating normally, the processing proceeds to step S 4047 . Meanwhile, if the power management apparatus  11  that has been returned to the state before updating is not operating normally, the updating cancelling process ends in this state. When the processing has proceeded to step S 4047 , the system management units  1125  of the plurality of power management apparatuses  11  that include the power management apparatus  11  that has been returned to the state before updating return the power management apparatus  11  that has been returned to the state before updating to the cooperative operation (step S 4047 ) and the updating cancelling process ends. 
     In this way, during updating, processes that separate a power management apparatus  11  to be updated from cooperative operation and return the power management apparatus  11  to cooperative operation when normal operation has been confirmed after updating are carried out. If the updating has failed, a process is also carried out that checks for normal operation after the power management apparatus has been returned to the state before updating and then returns the power management apparatus  11  to cooperative control if normal operation has been confirmed. By using this configuration, the updating can be carried out without affecting the power management apparatuses  11  that are operating cooperatively and ensures safe operation of the power management apparatuses  11 . 
     (2) Second Embodiment 
     (2-1) Overview of Second Embodiment 
     A local power management system is one sign of a transformation to a low-energy society, but at present, such systems are yet to become widespread due to the work necessary for installation. This situation means that it is important to add other attractive aspects to system installation and use so as to encourage more users to install systems and thereby realize a low-energy society. One example of such an additional attraction would be to provide entertainment (such as a game) that is linked to a local power management system. 
     Most video games currently on sale are fictional. Although some games, such as games relating to historical events or sports, use the names of real people and places and/or use actual footage in game video, the games themselves have no connection to actual society or to real life. For this reason, in a second embodiment of the present invention described below, a real-life game with a storyline where the game content itself can lead to reduced energy use in individual local power management systems (for example, household systems) is proposed. 
     In addition, games in the past have only been able to interest the user and provide satisfaction and a sense of achievement in the form of intangibles such as points, items collected within the game, and the clearing of stages. However, with system-linked entertainment such as that described below, effective gameplay and strategies in the game can be implemented in the operation of an actual local power management system. By doing so, the system-linked entertainment according to the present embodiment has aspects that lead to real-world benefits such as actual control over power, reducing power consumption, contributing to a reduction in CO 2 , and profiting from selling power, and at the same time has a tangible effect whereby the user can gain real-world knowledge. 
     As should be clear from the above, by using the system-linked entertainment described below, the user can have fun while engaging in an eco-friendly activity, such as reducing power consumption. 
     Note that although the present embodiment is an example applied to a local power management system, it is also possible to apply the present invention to any game that is linked to the real world and has tangible effects. 
     The system-linked entertainment is realized by the service providing unit  118  of the power management apparatus  11  operating so as to be linked to the various processing units of the power management apparatus  11  and a service providing server  31  (game service providing server) present outside the local power management system  1 . Also, by operating a control-compliant appliance  125  that is capable of connecting to the power management apparatus  11 , the user is capable of enjoying system-linked entertainment, as represented by a game. 
     (2-2) Configuration of Service Providing Unit 
     First, the configuration of the service providing unit  118  of the power management apparatus  11  will be described with reference to  FIGS. 76 and 77 .  FIGS. 76 and 77  are block diagrams useful in explaining the configuration of a service providing unit of the power management apparatus. 
     Note that it is assumed that the power management apparatus  11  according to the present embodiment includes the processing units of the power management apparatus  11  according to the first embodiment of the present invention and is capable of realizing the same functions as the power management apparatus  11  according to the first embodiment. 
     The service providing unit  118  is realized by a CPU, a ROM, a RAM, and the like, for example. As shown in  FIG. 76 , the service providing unit  118  includes a game service providing unit  1181  and an “other service” providing unit  1182 . 
     The game service providing unit  1181  is realized by a CPU, a ROM, a RAM, and the like, for example. The game service providing unit  1181  includes a game control unit  1701 , a parts library  1707 , and a contents library  1709 . 
     The game control unit  1701  is realized by a CPU, a ROM, a RAM, and the like, for example. The game control unit  1701  is a processing unit that links to the parts library  1707  and the game service providing server  31  and makes fundamental settings of a game, such as the background story and stages of the game. Also, when a game program stored in the contents library  1709  and/or the game service providing server  31  is being executed, the game control unit  1701  controls the execution of the game program to control how the game progresses. The game control unit  1701  includes a real world constructing unit  1703  and a virtual world constructing unit  1705 . 
     The real world constructing unit  1703  is realized by a CPU, a ROM, a RAM, and the like, for example. The real world constructing unit  1703  refers to a database stored in the storage unit  113  or the like of the power management apparatus  11  and constructs a real world in which information on the actual local power management system  1  is incorporated. 
     The virtual world constructing unit  1705  is realized by a CPU, a ROM, a RAM, and the like, for example. The virtual world constructing unit  1705  constructs a virtual world that is provided in advance in a content program. 
     The game control unit  1701  realizes the system-linked entertainment while linking the real world constructing unit  1703  and the virtual world constructing unit  1705  to one another. 
     The game control unit  1701  is capable of accessing a database in the power management apparatus  11  and also has a control execution path for the power management apparatus  11 . 
     The game controlled by the game control unit  1701  includes members of another local power management system  1  in the characters and enables users to enjoy match-ups or to remotely operate the game as members of a role playing game. Note that when the participation of members of other systems is permitted, the members of such other systems should preferably be prevented from accessing the real world for the present system  1 . 
     The parts library  1707  is a database provided in the game service providing unit  1181 . Information relating to parts such as virtual furniture, virtual appliances, and characters that appear in game contents and items and the like that appear during a game is recorded in the parts library  1707 . Note that the parts library  1707  may be present in the game service providing server  31 . 
     The contents library  1709  is another database provided in the game service providing unit  1181 . Various actual programs of game contents that can be executed by the power management apparatus  11  are stored in the contents library  1709 . 
       FIG. 77  shows one example of a game content stored in the contents library  1709 . A specific example of a game content will be described in brief below. 
     Room Makeover (Real World Game) 
     This is a game with a concept of changing the layout of furniture and household appliances from the present layout of a room, coordinating curtains and carpets, buying new furniture and household appliances, and competing to produce an interior design with the best colors and taste. This game makes it possible for the user to grasp how the total amount of power used by appliances changes as a result of changing the room layout or to grasp what happens to the amount of power when a new household appliance has been bought and set up. Here, libraries that are capable of displaying items with real-world attributes such as the manufacturer, design, and power consumption are provided. Such libraries may be stored in the game service providing server  31 . For improved items that are linked to the real world, it is possible to implement “result application mode” (a mode where game results are applied to the real-world system). 
     See Off the Power Eaters! (Real World+Virtual World Game) 
     The game displays current power usage in the present room and turns off unnecessary lights. The game also allows the user to compete to reduce power and/or to profit from selling more electricity by making adjustments to lighting, volume, and the like. Result application mode can be implemented for this part of the game. The game also has a concept of a virtual world in which “power eaters” go around turning on lights and the user competes to fight off such “power eaters” as best as he/she can. 
     Ultimate Lifestyle Adventure Team (Real World+Virtual World Game) 
     This game is composed of a stage where users aim to achieve the ultimate low consumption lifestyle using appliances that are present in the actual home and a stage where users aim for the ultimate lifestyle using appliances in a virtual home. 
     Save the Earth! Regreening Megaproject (Virtual World Game) 
     This game has a concept where the user tries to survive the global warming crisis caused by CO 2  emissions. The user assumes the role of the environment minister of a country and progresses through stages while grasping domestic public opinion and negotiating with other countries. This is an intelligent game that is capable of using real-world statistics and situations to enable advanced learning about the environment. 
     Role Playing Game (Real World+Virtual World Game) 
     This game has a stage that links only the first floor to the real world, with other stages providing virtual environments (as examples, a garden, a storehouse, and a closed room) in a matching form in which a story then progresses. In the real world stage, result application mode can be implemented for game results that can be reflected in the power state. 
     (2-3) Linking to Database 
     Next, linking to a database of the power management apparatus  11  in which various information showing a state of the real-world local power management system  1  is stored will be described with reference to  FIG. 78 .  FIG. 78  is a diagram useful in explaining linking to a database in a power management apparatus. 
     As examples, the data shown below is stored in a database stored in the power management apparatus  11 .
         appliance information on control-compliant appliances, electric vehicles, power generating apparatuses, power storage apparatuses, batteries of appliances, control-compliant outlets, outlet expansion apparatuses, and the like   power information (usage/power storage state) and position information relating to the apparatuses described above   registered users and access rights   power billing information and account information   time, weather, temperature       

     By using such data, the game control unit  1701  reproduces the real world in a game. 
     By arranging such appliances, the real world constructing unit  1703  is capable of imagining the overall floor plan of a game stage. For example, it is possible to imagine a floor plan, by assuming that the presence of a refrigerator or the like denotes a dining area, a personal computer or lamp denotes a private room, a washing machine denotes a bathroom or washroom area, an electric vehicle denotes a garage, and a light denotes a corridor. The real world constructing unit  1703  decides a floor plan based on such assumptions, and arranges items representing appliances, furniture, and the like from the parts library  1707 . 
     The real world constructing unit  1703  decides the characters of a game based on the registered user information. In a real world, actual appliances and attributes of items are linked, so that it is possible to display such appliances and in result application mode to carry out actions such as switching the power off. Accordingly, when an object such as an icon of an appliance disposed on a display screen or the like has been selected by the user, various information written in a database, such as appliance information, power information, and the like of the selected appliance, is displayed. 
     Since the game stages will be limited when only the real world is used in the game, the virtual world constructing unit  1703  adds a virtual world set in advance in the game contents to the game stages set based on the real world to configure more game stages (story backgrounds). 
     In  FIG. 78 , a state where the real world is display in a display area of a display device is shown. The user is capable of enjoying the game on this stage while operating the main character. 
     (2-4) Security for System-Linked Entertainment 
     Next, security for the system-linked entertainment will be described with reference to  FIG. 79 .  FIG. 79  is a diagram useful in explaining security for the system-linked entertainment. 
     In a system that carries out the present game, it is preferable to pay attention to the following three points regarding security.
     (1) There is the risk of a power management apparatus breaking down, of control rights over result application mode being compromised, of confidential information in the power management apparatus being leaked and the like due to participation of an anonymous third party accepted by a game on a power management apparatus or an attack from a malicious third party that uses such connection.   (2) A game on a power management apparatus is executed from a malicious third-party appliance and harmful activity is implemented.   (3) Confidential information (account/billing information and the like) leaks between a power management apparatus and a service providing server (power sales management server) related to selling power.
 
Security Risk 1
   

     First, when an anonymous third party accepted by a game on a power management apparatus participates, the game is designed so as to limit such participation to a stage composed of only a virtual world, thereby preventing confidential information in the power management apparatus from leaking from the game. 
     Next, to stop attacks from a malicious third party, it is necessary to prevent the third party from freely controlling the power management apparatus. To do so, by installing virus removing software into the power management apparatus, third-party attacks are detected and/or removed. Further protection against attacks is provided by using an electronic watermark to prevent the power management apparatus from being taken over and by using the analysis server  34  to detect suspicious repeated attacks and the like from the execution history and prevent execution and/or cut off the connection. 
     Security Risk 2 
     Appliances and players check whether a member is a legitimate member who is allowed to play the game. Even if the member is a legitimate member, since it is not preferable for children to engage in activities such as selling power, access to the game itself is divided into levels and settings of whether a member has access rights and/or can implement result application mode are made. When other users are permitted to play, control is carried out to prevent the story from using real world information. 
     Accordingly, appliances and users are set in advance in the power management apparatus, access levels are assigned, and authentication is carried out for both appliances and users. This authentication can use the same scheme as the methods shown in the first embodiment that use a public key or common key or both. It is also preferable to include an arrangement for implementing authentication at specified intervals in the game. It is also preferable to prevent the database from being accessed while a user without access rights is using the game. 
     Security Risk 3 
     It is preferable to implement security measures during the selling of power, not just for the present game. This should not be problematic if authentication of services by the local power management system  1  via the Internet is functioning. 
     (2-5) Flow of System-Linked Entertainment 
     Next, the flow of system-linked entertainment provided by a power management apparatus  11  according to the present embodiment will be described with reference to  FIGS. 80 to 81B .  FIGS. 80 to 81B  are flowcharts useful in explaining the flow of system-linked entertainment. Note that  FIGS. 80 to 81B  are used to explain a game as one example of system-linked entertainment. 
     Note that it is assumed that before the following explanation begins, a user who wishes to play a game linked to the local power management system  1  plays the game by operating a display terminal (for example, a display appliance such as a television set, or a portable appliance such as a mobile telephone or a mobile game console) that has a display screen and is capable of connecting to the power management apparatus  11 . The appliance used by the user to play the game may also be the power management apparatus  11  itself. 
     First, the overall flow will be described with reference to  FIG. 80 . 
     First, the user turns on the power of a display terminal  125  to activate the terminal itself (step S 5001 ). After activating the terminal, the user selects an object such as an icon for launching the game and thereby requests the power management apparatus  11  to launch the game. 
     The power management apparatus  11  that has received the request implements a process that authenticates the display terminal to judge whether the display terminal that requested the launching of the game is a managed appliance that is managed by the power management apparatus  11  itself (step S 5003 ). Also, as shown in detail in  FIGS. 81A and 81B , since the functions of the game provided to the user will differ depending on whether the display terminal is a managed appliance, the power management apparatus  11  checks the setting information (step S 5005 ) and confirms which functions can be provided. After this, the power management apparatus  11  launches the game program (step S 5007 ) and transmits the necessary data types to the display terminal. 
     The display terminal receives the data types transmitted from the power management apparatus  11  and displays an initial screen of the game on a display screen of the display terminal  125  (step S 5009 ). The user selects an object such as an icon that represents a game and is displayed in the initial screen (step S 5011 ) to specify a game content that the user wishes to play. Here, the games displayed on the display screen are games that the user is permitted to execute out of the games stored in the contents library  1709  or the like. 
     The user operates an input apparatus (a mouse, keyboard, touch panel, or the like) of the display terminal  125  to start the game (step S 5013 ). In accordance with the progress of the game on the display terminal, the power management apparatus  11  loads individual data, prepares data, and/or stores a game content (step S 5015 ). 
     There are cases where at an arbitrary time during the game, the user requests a start of result application mode where game results are applied to the actual system (step S 5017 ). The power management apparatus  11  that has received the request checks whether execution of result application mode is possible by the user who made the start request for result application mode (step S 5019 ). After checking the setting information and the like to check the access rights and execution rights of the user and thereby confirm the execution risk (step S 5020 ), the power management apparatus  11  presents the range of executable actions out of result application mode to the display terminal (step S 5021 ). 
     At the display terminal, the content presented from the power management apparatus  11  is displayed on the display screen and the user is invited to select the execution content (step S 5023 ). The display terminal informs the power management apparatus  11  of the content of the user&#39;s selection. 
     In accordance with the selection result of the user, the power management apparatus  11  issues a suitable execution instruction for the selection result to the power distribution apparatus in accordance with the selection result of the user (step S 5025 ). The power management apparatus  11  updates the log information (step S 5027 ) and informs the user that the execution of result application mode has ended (step S 5029 ). 
     Next, the detailed flow of the system-linked entertainment will be described with reference to  FIGS. 81A and 81B . 
     As described earlier, the user operates an appliance that executes the game to launch the game, with the game service providing unit  1181  of the power management apparatus  11  awaiting a start request for the game to be transmitted from the display terminal (step S 5031 ). 
     When a game start request has been transmitted from the display terminal, the power management apparatus  11  implements appliance authentication of the display terminal that transmitted the game start request (step S 5033 ). By doing so, the power management apparatus  11  is capable of checking whether the display terminal that has requested the start of a game is a managed appliance that is managed by the power management apparatus  11  itself (step S 5035 ). 
     When the display terminal is not a managed appliance, the game service providing unit  1181  of the power management apparatus  11  checks whether the user of the power management apparatus  11  is permitted to start the game (step S 5037 ) and if the user of the power management apparatus  11  is not permitted to execute the game, the processing ends. When the user of the power management apparatus  11  is permitted to execute the game, the game service providing unit  1181  of the power management apparatus  11  implements step S 5039 , described below. 
     Meanwhile, if the display terminal is a managed appliance, or is not a managed appliance but has obtained permission from the user of the power management apparatus  11  to execute the game, the game service providing unit  1181  of the power management apparatus  11  carries out user authentication (step S 5039 ). 
     If the game service providing unit  1181  of the power management apparatus  11  has confirmed that the user is a member registered in the power management apparatus  11 , the access level of the game and a control level for result application mode are set from the level of the control rights of the user (step S 5041 ). 
     Next, the game service providing unit  1181  of the power management apparatus  11  launches the main program of the game (step S 5043 ) and has an initial display of the game displayed on the display terminal used by the user. 
     Once the user of the display terminal has selected a game content which the user wishes to play, the selection result is transmitted to the power management apparatus  11  so that the game service providing unit  1181  of the power management apparatus  11  can specify the selected game content (step S 5045 ). 
     The game service providing unit  1181  of the power management apparatus  11  checks whether the specified content is capable of being accessed by the user of the display terminal and whether result activation mode can be implemented (step S 5047 ). 
     When the game user does not have access rights or does not have authority to implement result application mode, the game service providing unit  1181  of the power management apparatus  11  makes settings so that access to the database and implementation of result determination mode are not possible while the game is activated (step S 5049 ). 
     When the game user has access rights and is capable of implementing result application mode, the power management apparatus  11  accesses the database and gathers appliance information and power information of the managed appliances (step S 5051 ). 
     The game control unit  1701  of the game service providing unit  1181  uses the various information gathered in step S 5051  to construct fundamental settings such as the story background of the game (step S 5053 ). When the constructing of the fundamental settings has ended, the game control unit  1701  carries out execution control over the selected game content based on the set story background (step S 5055 ). While this is happening, the power management apparatus  11  and the display terminal communicate interactively, so that the power management apparatus  11  displays game screens on the display of the terminal and information inputted by the user is transmitted from the display terminal. Also during this time, the game control unit  1701  of the power management apparatus  11  judges whether processing that requests an end of the game, suspension of the game, or the like has been made (step S 5057 ). 
     After a status such as end the game, suspend the game, or the like has been selected by the user, if the game is a content where activation of result application mode is possible, the game service providing unit  1181  of the power management apparatus  11  checks whether the user wishes to switch to result application mode (step S 5059 ). 
     If the user has selected not to switch to result application mode, the game service providing unit  1181  of the power management apparatus  11  checks whether the game content is to be saved and ends the game program. 
     Also, when switching to result application mode, the game service providing unit  1181  of the power management apparatus  11  confirms whether the user has execution rights for result application mode (step S 5061 ). If the user does not have execution rights for result application mode, the game service providing unit  1181  of the power management apparatus  11  ends the game program. 
     When the user has execution rights for result application mode, the game service providing unit  1181  of the power management apparatus  11  extracts control that can be implemented on actual appliances based on the content of the game from activation to the present point (step S 5063 ) and displays a list to the user. 
     Before displaying the list, the game service providing unit  1181  of the power management apparatus  11  should preferably implement a check for risks. More specifically, the game service providing unit  1181  should enquire to the analysis server  34  to check whether the control is suspicious based on the controllable content and the history thereof, and delete suspicious control from the extracted list mentioned above. By doing so, aside from risks relating to cyber attacks and the like, it is possible to check for risks relating to commands that turn off the power of appliances (for example, a household appliance such as a refrigerator) for which an uninterrupted connection is preferred. 
     The user of the game selects an item that the user wishes to implement such as “Switch Off Appliance A” from the list displayed on the display screen of the display terminal. The selection result is transmitted to the power management apparatus  11  and the power management apparatus  11  is capable of specifying the item content (step S 5065 ). 
     After this, in accordance with the user&#39;s selection result, the power management apparatus  11  issues an execution instruction in accordance with the selection result to the power distribution apparatus  121 , the control-compliant outlet  123 , the control-compliant appliance  125 , or the like (step S 5067 ). The power management apparatus  11  updates the log information (step S 5069 ) and checks whether all of the control has been carried out (step S 5071 ). 
     The power management apparatus  11  receives an execution end from the command target appliance and if all of the control has been carried out, displays an end message to the user (step S 5073 ). The power management apparatus  11  checks whether the game is to end or continue (step S 5075 ) and returns to step S 5055  when the game continues. Meanwhile, when the game is to end, the power management apparatus  11  ends the game. 
     By carrying out processing according to the flow described above, the power management apparatus is capable of providing the user with entertainment, such as a game, that is linked to a local power management system. As a result, the system-linked entertainment is capable of actually contributing to reductions in power and CO 2  as an attractive application of the local power management system. 
     Hardware Configuration 
     Next, the hardware configuration of the power management apparatus  11  according to the embodiment of the present invention will be described in detail with reference to  FIG. 82 .  FIG. 82  is a block diagram useful in explaining the hardware configuration of the power management apparatus  11  according to the embodiment of the present invention 
     The power management apparatus  11  mainly includes a CPU  901 , a ROM  903 , and a RAM  905 . Furthermore, the power management apparatus  11  also includes a host bus  907 , a bridge  909 , an external bus  911 , an interface  913 , an input device  915 , an output device  917 , a storage device  919 , a drive  921 , a connection port  923 , and a communication device  925 . 
     The CPU  901  serves as an arithmetic processing apparatus and a control device, and controls the overall operation or a part of the operation of the power management apparatus  11  according to various programs recorded in the ROM  903 , the RAM  905 , the storage device  919 , or a removable recording medium  927 . The ROM  903  stores programs, operation parameters, and the like used by the CPU  901 . The RAM  905  primarily stores programs used in execution of the CPU  901  and parameters and the like varying as appropriate during the execution. These are connected with each other via the host bus  907  configured from an internal bus such as a CPU bus or the like. 
     The host bus  907  is connected to the external bus  911  such as a PCI (Peripheral Component Interconnect/Interface) bus via the bridge  909 . 
     The input device  915  is operation means operated by a user, such as a mouse, a keyboard, a touch panel, buttons, a switch and a lever. Also, the input device  915  may be remote control means (a so-called remote control) using, for example, infrared light or other radio waves, or may be an externally connected device  929  such as a mobile phone or a PDA conforming to the operation of the power management apparatus  11 . Furthermore, the input device  915  generates an input signal based on, for example, information which is input by a user with the above operation means, and is configured from an input control circuit for outputting the input signal to the CPU  901 . The user of the power management apparatus  11  can input various data to the power management apparatus  11  and can instruct the power management apparatus  11  to perform processing by operating this input apparatus  915 . 
     The output device  917  is configured from a device capable of visually or audibly notifying acquired information to a user. Examples of such device include display devices such as a CRT display device, a liquid crystal display device, a plasma display device, an EL display device and lamps, audio output devices such as a speaker and a headphone, a printer, a mobile phone, a facsimile machine, and the like. For example, the output device  917  outputs a result obtained by various processings performed by the power management apparatus  11 . More specifically, the display device displays, in the form of texts or images, a result obtained by various processes performed by the power management apparatus  11 . On the other hand, the audio output device converts an audio signal such as reproduced audio data and sound data into an analog signal, and outputs the analog signal. 
     The storage device  919  is a device for storing data configured as an example of a storage unit of the power management apparatus  11  and is used to store data. The storage device  919  is configured from, for example, a magnetic storage device such as a HDD (Hard Disk Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device. This storage device  919  stores programs to be executed by the CPU  901 , various data, and various data obtained from the outside. 
     The drive  921  is a reader/writer for recording medium, and is embedded in the power management apparatus  11  or attached externally thereto. The drive  921  reads information recorded in the attached removable recording medium  927  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, and outputs the read information to the RAM  905 . Furthermore, the drive  921  can write in the attached removable recording medium  927  such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory. The removable recording medium  927  is, for example, a DVD medium, an HD-DVD medium, or a Blu-ray medium. The removable recording medium  927  may be a CompactFlash (CF; registered trademark), a flash memory, an SD memory card (Secure Digital Memory Card), or the like. Alternatively, the removable recording medium  927  may be, for example, an IC card (Integrated Circuit Card) equipped with a non-contact IC chip or an electronic appliance. 
     The connection port  923  is a port for allowing devices to directly connect to the power management apparatus  11 . Examples of the connection port  923  include a USB (Universal Serial Bus) port, an IEEE1394 port, a SCSI (Small Computer System Interface) port, and the like. Other examples of the connection port  923  include an RS-232C port, an optical audio terminal, an HDMI (High-Definition Multimedia Interface) port, and the like. By the externally connected apparatus  929  connecting to this connection port  923 , the power management apparatus  11  directly obtains various data from the externally connected apparatus  929  and provides various data to the externally connected apparatus  929 . 
     The communication device  925  is a communication interface configured from, for example, a communication device for connecting to a communication network  931 . The communication device  925  is, for example, a wired or wireless LAN (Local Area Network), Bluetooth (registered trademark), a communication card for WUSB (Wireless USB), or the like. Alternatively, the communication device  925  may be a router for optical communication, a router for ADSL (Asymmetric Digital Subscriber Line), a modem for various communications, or the like. This communication device  925  can transmit and receive signals and the like in accordance with a predetermined protocol such as TCP/IP on the Internet and with other communication devices, for example. The communication network  931  connected to the communication device  925  is configured from a network and the like, which is connected via wire or wirelessly, and may be, for example, the Internet, a home LAN, infrared communication, radio wave communication, satellite communication, or the like. 
     Heretofore, an example of the hardware configuration capable of realizing the functions of the power management apparatus  11  according to the embodiment of the present invention has been shown. Each of the structural elements described above may be configured using a general-purpose material, or may be configured from hardware dedicated to the function of each structural element. Accordingly, the hardware configuration to be used can be changed as appropriate according to the technical level at the time of carrying out the present embodiment. 
     Since the hardware configurations of the control-compliant appliance  125  and the analysis server  34  according to the present embodiment of the invention are the same as the configuration of the power management apparatus  11  according to the present embodiment of the invention, detailed description thereof is omitted. 
     Although preferred embodiments of the present invention have been described in detail with reference to the attached drawings, the present invention is not limited to the above examples. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof. 
     The present application contains subject matter related to that disclosed in Japanese Priority Patent Application JP 2010-013677 filed in the Japan Patent Office on Jan. 25, 2010, the entire content of which is hereby incorporated by reference.