Patent Publication Number: US-11663865-B2

Title: Key information sharing system, delivery device and user terminal

Description:
INCORPORATION BY REFERENCE 
     This application is a continuation of and claims priority to U.S. patent application Ser. No. 16/185,229, filed on Nov. 9, 2018, which claims priority to Japanese Patent Application No. 2017-218503, filed on Nov. 13, 2017. The benefit of priority is claimed to each of the foregoing, and the entire contents of each of the foregoing are incorporated herein by reference. 
    
    
     BACKGROUND 
     1. Technical Field 
     The disclosure relates to a key information sharing system that allows key information for a control device equipped in an object to be shared, a delivery device that delivers the key information, and a user terminal that receives the key information delivered from the delivery device. 
     2. Description of Related Art 
     In recent years, there has been developed a system (hereinafter, also referred to as a “key system”) that transmits key information from the exterior to a control device equipped in an object such as a vehicle or a facility, with a user terminal such as a smartphone, and thereby makes the control device perform a predetermined control to the object. Here, the key information is information associated with the object, and is information for putting the object into an available state. 
     As such a key system, for example, there is known a system that transmits the key information from a user terminal to an in-vehicle device mounted on a vehicle, and thereby makes the in-vehicle device perform a predetermined control such as a locking-unlocking control of locking or unlocking a door of the vehicle. Japanese Patent Application Publication No. 2015-169008 discloses a system that allows operation of a vehicle in the case where a key authentication succeeds between an electronic key (smart key) and the vehicle by matching in comparison with identification information transmitted from the electronic key to the vehicle and where a terminal authentication succeeds between the vehicle and a portable terminal that are performing pairing. 
     Further, Japanese Patent Application Publication No. 2012-41709 discloses a technology for transferring, to a third party, key information about a particular vehicle that is included in an electronic key possessed by a user. In the technology disclosed in JP 2012-41709 A, first, a user terminal possessed by the user receives the key information from the electronic key of the user by short-range wireless communication. Next, the user terminal transmits the key information to a third-party terminal possessed by the third party. Then, an electronic key of the third party receives the key information received by the third-party terminal by short-range wireless communication. Thereby, the electronic key of the third party can be used as a key for the particular vehicle. 
     SUMMARY 
     In some cases, the key information to be used in the key systems described above is delivered from a delivery device to the user terminal. In this case, at a time of utilization of a particular object, the user receives key information for a control device equipped in the object (that is, key information associated with the particular object) from the delivery device through the user terminal. Thereby, the user can utilize the particular object, using the user terminal. 
     Here, in the case where the user shares the particular object with a third party or lends the particular object to the third party, the user needs to lend the user terminal itself to the third party at the time of the utilization of the object by the third party, if only the user terminal has the key information and the third-party terminal possessed by the third party does not have the key information. However, such a situation significantly decreases convenience at a time of the sharing and lending of the object. 
     Further, for sharing the key information between the user terminal and the third-party terminal, it is possible that key information for lending is generated in the user terminal and the key information for lending is transferred from the user terminal to the third-party terminal. However, when the key information is generated in the user terminal and the generated key information is transferred from the user terminal to the third-party terminal, there is a possibility of the decrease in the security of the object. 
     The disclosure provides a technology that allows the key information for the control device equipped in the object to be shared by the user terminal and the third-party terminal while the security is ensured. 
     A key information sharing system according to a first aspect of the disclosure relates to a key information sharing system that allows key information as first information to be shared. The first information is associated with an object equipped with a control device, the control device performing a predetermined control to the object when the control device receives the first information from an external terminal. The key information sharing system according to the first aspect of the disclosure includes: a delivery device configured to deliver the first information; and a user terminal configured to receive the first information delivered from the delivery device. The delivery device includes an information generation unit configured to add second information to the first information that is delivered to the user terminal, the second information being information that allows the first information to be transferred between the user terminal and the third-party terminal without the delivery device. The user terminal includes a terminal-to-terminal communication unit configured to transmit the first information to the third-party terminal in response to an input operation by a user, when the user terminal receives the first information to which the second information has been added, from the delivery device. 
     In the key information sharing system according to the disclosure, when the control device equipped in the object receives the first information associated with the object, from the terminal in the exterior of the object, the control device performs the predetermined control to the object. Here, the control device may perform a predetermined authentication process for the first information received from the external terminal. In this case, when the authentication of the first information succeeds, the control device performs the predetermined control to the object. The external terminal is not limited to the user terminal, and even when the control device receives the first information from the third-party terminal, the control device can perform the predetermined control to the object. 
     The predetermined control is a control that is allowed to be performed when the control device receives the first information. For example, the predetermined control may include a locking-unlocking control of locking or unlocking the object. In the case where the object is a vehicle, the predetermined control may include a control of allowing a driving source (an internal combustion engine or a motor) of the vehicle to be started. In the case where the object is a facility, the predetermined control may include a control of turning on an electric power source of an electric product in the facility. 
     In the key information sharing system according to the aspect, the first information is delivered from the delivery device. Then, the user receives the first information delivered by the delivery device, through the user terminal. At this time, in the delivery device, the information generation unit adds the second information, which is the information that allows the first information to be transferred between the user terminal and the third-party terminal without the delivery device, to the first information that is delivered to the user terminal. That is, by adding the second information to the first information, the first information is allowed to be transferred from the user terminal to the third-party terminal. In other words, when the user terminal receives the first information to which the second information has not been added, the user terminal cannot transmit the first information to the third-party terminal. Therefore, only when the user terminal receives the first information to which the second information has been added, the user terminal, with the terminal-to-terminal communication unit, transmits the first information to the third-party terminal, in response to the input operation by the user. 
     With the key information sharing system according to the aspect, only the first information to which the second information has been added on the delivery device side is transmitted or received between the user terminal and the third-party terminal. That is, the first information to be transferred to the third-party terminal is also delivered from the delivery device. Thereby, the first information to be transferred from the user terminal to the third-party terminal can be recorded or managed on the delivery device side. Accordingly, the first information can be shared by the user terminal and the third-party terminal while the security is ensured. 
     In the key information sharing system according to the aspect, the information generation unit may further add third information to the first information when the information generation unit adds the second information to the first information, the third information being information that restricts the predetermined control that is allowed to be performed to the object when the control device receives the first information. Then, the user terminal may transmit the first information to which the third information has been added from the terminal-to-terminal communication unit to the third-party terminal, when the user terminal receives the first information to which the second information and the third information have been added, from the delivery device. Thereby, the third-party terminal receives the first information to which the third information has been added. Therefore, when the first information is transmitted from the third-party terminal to the control device, the predetermined control that is allowed to be performed to the object by the control device is restricted. Accordingly, the predetermined control that is allowed to be performed to the object by the control device can be restricted, when the third party utilizes the object using the third-party terminal. 
     The information generation unit may set a restriction content for the predetermined control, based on a function restriction request transmitted from the user terminal to the delivery device, and may add the third information to the first information, the restriction content being contained in the third information. Thereby, the user sets the content of the function restriction request that is delivered from the user terminal to the delivery device, and thereby, the user can determine the restriction content about the predetermined control that is allowed to be performed to the object by the control device when the third party transmits the first information from the third-party terminal to the control device. 
     Here, the user terminal may further include a registration unit configured to register a plurality of the third-party terminals while grouping the plurality of the third-party terminals into a plurality of groups. Then, the user terminal may set the restriction content in the function restriction request for each of the groups and may transmit the function restriction request to the delivery device. In this case, the information generation unit may add the third information corresponding to the function restriction request set for each of the groups, to the first information. Thereby, for each of the groups, the user can set the restriction content about the predetermined control that is allowed to be performed to the object by the control device when the first information is transmitted from the third-party terminal to the control device. 
     In the key information sharing system according to the aspect, the information generation unit may further add fourth information to the first information in the delivery device when the information generation unit adds the second information to the first information, the fourth information being information that restricts use of the first information by the third-party terminal. Then, the user terminal may transmit the first information to which the fourth information has been added from the terminal-to-terminal communication unit to the third-party terminal, when the user terminal receives the first information to which the second information and the fourth information have been added, from the delivery device. Thereby, the third-party terminal receives the first information to which the fourth information has been added. Accordingly, when the third party transmits the first information from the third-party terminal to the control device, it is possible to provide the restriction about the utilization of the object. 
     The information generation unit may set a restriction content for the first information, based on a use restriction request transmitted from the user terminal to the delivery device, and may add the fourth information to the first information, the restriction content being contained in the fourth information. Thereby, the user sets the content of the use restriction request that is delivered from the user terminal to the delivery device, and thereby, the user can determines the restriction content about the utilization of the object when the third party transmits the first information from the third-party terminal to the control device. 
     Here, the fourth information may contain information that restricts a use period or the number of times of use in which the third-party terminal is allowed to validly use the first information. In the case where the third-party terminal receives the first information to which the fourth information has been added, the period or the number of times in which the predetermined control is allowed to be performed to the object by the control device when the third-party terminal transmits the first information to the control device is restricted. Accordingly, it is possible to restrict the period or the number of times in which the third party is allowed to utilize the object. Further, in the case where the object is a movable body such as a vehicle, the fourth information may contain information that restricts a region in which the third-party terminal is allowed to validly use the first information. In the case where the third-party terminal receives the first information to which the fourth information has been added, the region in which the predetermined control is allowed to be performed to the movable body (object) by the control device when the third-party terminal transmits the first information to the control device is restricted. Accordingly, it is possible to restrict the region in which the third party is allowed to utilize the movable body (object). 
     In the case where the user terminal further includes a registration unit configured to register a plurality of the third-party terminals while grouping the plurality of the third-party terminals into a plurality of groups, the user terminal may set the restriction content in the use restriction request for each of the groups and may transmit the use restriction request to the delivery device. In this case, in the delivery device, the information generation unit adds the fourth information corresponding to the use restriction request set for each of the groups, to the first information. Thereby, for each of the groups, the user can set the restriction content about the utilization of the object when the third party transmits the first information from the third-party terminal to the control device. 
     In the key information sharing system according to the aspect, the information generation unit may further add fifth information to the first information when the information generation unit adds the second information to the first information, the fifth information being information that allows the first information to be transferred only between the user terminal and a particular third-party terminal belonging to a particular group without the delivery device. Then, the user terminal may transmit the first information only to the particular third-party terminal, when the user terminal receives the first information to which the second information and the fifth information have been added, from the delivery device. Thereby, it is possible to restrict a sharer for the first information, only to the particular third-party terminal. 
     The information generation unit may generate the fifth information based on information about the particular third-party terminal that is transmitted from the user terminal to the delivery device, and may add the fifth information to the first information. Thereby, the user can determine the particular group with which the first information is shared. 
     In the key information sharing system according to the aspect, on the user terminal side, the third information may be added to the first information that is transmitted from the user terminal to the third-party terminal. In this case, the user terminal adds the third information to the first information, and transmits the first information to which the third information has been added, to the third-party terminal, when the user terminal receives the first information to which the second information has been added, from the delivery device. 
     At this time, in the case where the user terminal further includes a registration unit configured to register a plurality of the third-party terminals while grouping the plurality of the third-party terminals into a plurality of groups, the user terminal may set the restriction content in the third information for each of the groups. 
     In the key information sharing system according to the aspect, on the user terminal side, the fourth information may be added to the first information that is transmitted from the user terminal to the third-party terminal. In this case, the user terminal adds the fourth information to the first information, and transmits the first information to which the fourth information has been added, to the third-party terminal, when the user terminal receives the first information to which the second information has been added, from the delivery device. 
     At this time, in the case where the user terminal further includes a registration unit configured to register a plurality of the third-party terminals while grouping the plurality of the third-party terminals into a plurality of groups, the user terminal may set the restriction content in the fourth information for each of the groups. 
     In the key information sharing system according to the aspect, on the user terminal side, the fifth information may be added to the first information. In this case, the user terminal adds the fifth information to the first information, and transmits the first information only to a particular third-party terminal, when the user terminal receives the first information to which the second information has been added, from the delivery device. 
     A delivery device according to a second aspect of the disclosure includes: an information transmitting unit configured to deliver key information as first information to a user terminal; and an information generation unit configured to add second information to the first information that is delivered to the user terminal, the second information being information that allows the first information to be transferred between the user terminal and a third-party terminal without the delivery device. The first information is associated with an object equipped with a control device, and the control device performs a predetermined control to the object when the control device receives the first information from an external terminal. 
     In the delivery device according to the aspect, the information generation unit may further add third information to the first information when the information generation unit adds the second information to the first information. At this time, the information generation unit may set a restriction content for the predetermined control, based on a function restriction request transmitted from the user terminal, and may add the third information to the first information, the restriction content being contained in the third information. 
     In the delivery device according to the aspect, the information generation unit may further add fourth information to the first information when the information generation unit adds the second information to the first information. At this time, the information generation unit may set a restriction content for the first information, based on a use restriction request transmitted from the user terminal, and may add the fourth information to the first information, the restriction content being contained in the fourth information. 
     In the delivery device according to the aspect, the information generation unit may further add fifth information to the first information when the information generation unit adds the second information to the first information. At this time, the information generation unit may further generate the fifth information based on information about a particular group that is transmitted from the user terminal, and may add the fifth information to the first information. 
     A user terminal according to a third aspect of the disclosure includes a terminal-to-terminal communication unit configured to transmit the first information to the third-party terminal in response to an input operation by a user, when the user terminal receives the first information to which the second information has been added, from the delivery device according to the second aspect of the disclosure. 
     According to the disclosure, the first information for the control device equipped in the object can be shared by the user terminal and the third-party terminal while the security is ensured. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features, advantages, and technical and industrial significance of exemplary embodiments will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein: 
         FIG.  1    is a diagram showing an overview of a key system according to an embodiment; 
         FIG.  2    is a block diagram schematically showing an exemplary configuration of a portable terminal, a server device and a vehicle control device mounted on a vehicle that are shown in  FIG.  1   ; 
         FIG.  3    is a diagram showing a flow of processes and data when a door of the vehicle is unlocked; 
         FIG.  4    is a diagram for describing a transfer of authentication information from a user terminal to a third-party terminal according to a first embodiment; 
         FIG.  5    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal to the third-party terminal according to the first embodiment; 
         FIG.  6    is a diagram showing an operation screen of a touch panel display included in an input-output unit of a user terminal according to a second embodiment; 
         FIG.  7    is a diagram for describing a transfer of the authentication information from the user terminal to the third-party terminal according to the second embodiment; 
         FIG.  8    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal to the third-party terminal according to the second embodiment; 
         FIG.  9    is a diagram showing a flow of processes and data when the door of the vehicle is unlocked according to the second embodiment; 
         FIG.  10    is a first diagram showing an operation screen of a touch panel display included in an input-output unit of a user terminal according to a third embodiment; 
         FIG.  11    is a second diagram showing an operation screen of the touch panel display included in the input-output unit of the user terminal according to the third embodiment; 
         FIG.  12    is a diagram for describing a transfer of the authentication information from the user terminal to the third-party terminal according to the third embodiment; 
         FIG.  13    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal to the third-party terminal according to the third embodiment; 
         FIG.  14    is a diagram showing an operation screen of a touch panel display included in an input-output unit of a user terminal according to a fourth embodiment; 
         FIG.  15    is a diagram for describing a transfer of the authentication information from the user terminal to the third-party terminal according to the fourth embodiment; and 
         FIG.  16    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal to the third-party terminal according to the fourth embodiment. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     Hereinafter, specific embodiments of the disclosure will be described based on the drawings. Dimensions, materials, shape, relative dispositions and others of constituent components described in the embodiments are not intended to limit the technical scope of the disclosure to the embodiments, unless otherwise mentioned. 
     First Embodiment 
     Here, an embodiment in the case where the disclosure is applied to a system allowing a user terminal and a third-party terminal to share authentication information for utilizing a particular vehicle will be described. 
     Overview of Key System 
       FIG.  1    is a diagram showing an overview of a key system according to the embodiment. The key system according to the embodiment is configured to include a vehicle control device  11  mounted on a vehicle  10 , a portable terminal  200 , and a server device  400 . The portable terminal  200  is a terminal possessed by a person who utilizes the vehicle  10 . The server device  400  is a delivery device that delivers authentication information associated with the vehicle  10 . 
     In the key system according to the embodiment, the portable terminal  200  and the server device  400  are connected to each other through a network such as the internet that is a public communication network. When the server device  400  receives a delivery request from the portable terminal  200 , the server device  400  delivers the authentication information to the portable terminal  200 . Further, the portable terminal  200  transmits the authentication information received from the server device  400 , to the vehicle control device  11  mounted on the vehicle  10 , by short-range wireless communication. The vehicle control device  11  authenticates the authentication information received from the portable terminal  200 . When the authentication of the authentication information succeeds, the vehicle control device  11  can control the vehicle  10 . In the embodiment, the vehicle  10  corresponds to the “object”, and the vehicle control device  11  corresponds to the “control device”. Further, in the embodiment, the authentication information corresponds to the “key information” (first information), and the server device  400  corresponds to the “delivery device”. 
     System Configuration of Key System 
     Each constituent element of the key system according to the embodiment will be described based on  FIG.  2   .  FIG.  2    is a block diagram schematically showing an exemplary configuration of the portable terminal  200 , the server device  400  and the vehicle control device  11  mounted on the vehicle  10  that are shown in  FIG.  1   . The vehicle control device  11  includes a key unit  100  that performs communication with the portable terminal  200  and a control device  300  that executes various controls to the vehicle  10 . 
     Specifically, the control device  300  executes a locking-unlocking control of locking or unlocking a door of the vehicle  10  by controlling a door lock actuator  12  of the vehicle  10 . Further, the control device  300  executes an engine control such as a start control of starting an engine  13  that is a driving source of the vehicle  10 . In the vehicle  10 , the control device  300  executes the various controls by transmitting and receiving electric waves in a radio frequency (hereinafter, referred to as RF) band and a low frequency (hereinafter, referred to as LF) band to and from the key unit  100 . 
     The control device  300  is configured to include an LF transmitter  301 , an RF receiver  302 , a matching ECU  303 , a body ECU  304 , and an engine ECU  305 . The LF transmitter  301  is a device that transmits an electric wave in an LF band (for example, 100 KHz to 300 KHz) for searching (polling) the key unit  100 . The RF receiver  302  is a device that receives an electric wave in an RF band (for example, 100 MHz to 1 GHz) transmitted from the key unit  100 . 
     The matching ECU  303  is a computer that controls the body ECU  304  and the engine ECU  305  based on a command signal that is transmitted from the key unit  100  with the electric wave in the RF band. For example, the matching ECU  303  is constituted by a microcomputer. The matching ECU  303  authenticates the command signal transmitted from the key unit  100 , based on whether the command signal is a signal transmitted from a valid device. Specifically, the matching ECU  303  determines whether a key ID contained in the command signal coincides with a key ID previously stored in a storage unit included in the matching ECU  303 . 
     When the authentication of the key ID succeeds, the matching ECU  303  transmits a command corresponding to the command signal, to the body ECU  304  and the engine ECU  305 , through an in-vehicle network such as a controller area network (CAN). Specifically, when the command signal received from the key unit  100  is a locking signal, the matching ECU  303  transmits a locking command for locking the door of the vehicle  10 , to the body ECU  304 . When the command signal received from the key unit  100  is an unlocking signal, the matching ECU  303  transmits an unlocking command for unlocking the door of the vehicle  10 , to the body ECU  304 . When the command signal received from the key unit  100  is an engine start permission signal, the matching ECU  303  transmits an engine start permission command for allowing the engine  13  of the vehicle  10  to be started, to the engine ECU  305 . 
     The body ECU  304  is a computer that performs a body control for the vehicle  10 . The body ECU  304  is electrically connected to the door lock actuator  12  that performs the locking and unlocking of the door of the vehicle  10 . The body ECU  304  has a function to lock and unlock the door of the vehicle  10  by controlling the door lock actuator  12  based on the locking command or unlocking command received from the matching ECU  303 . 
     The engine ECU  305  is a computer that controls the engine  13  of the vehicle  10 . The engine ECU  305  is electrically connected to various apparatuses for controlling the engine  13 , as exemplified by a fuel injection valve, an ignition plug, a throttle valve, and starter (each of which is not illustrated). When the engine ECU  305  receives the engine start permission command from the matching ECU  303 , the engine ECU  305  is put into an engine start allowing state in which the stopped engine  13  can be started. The engine start allowing state is a state in which the engine ECU  305  can perform a start control for the engine  13  when an ignition switch (or a push start switch) is turned on in the vehicle  10 . 
     Next, the key unit  100  will be described. The key unit  100  is a device that is disposed at a predetermined position (for example, the interior of a glove box) in a vehicle cabin of the vehicle  10 . The key unit  100  has a function to authenticate the portable terminal  200  by performing short-range wireless communication with the portable terminal  200 , and a function to transmit a command signal to the control device  300  using an electric wave in an RF band, based on the authentication result. The key unit  100  is configured to include an LF receiver  101 , an RF transmitter  102 , a short-range communication unit  103 , and a control unit  104 . 
     The LF receiver  101  is a device that receives a polling signal transmitted from the control device  300  with an electric wave in an LF band. The RF transmitter  102  is a device that transmits a command signal to the control device  300  with an electric wave in an RF band. The short-range communication unit  103  is a device that performs communication with the portable terminal  200  in the exterior of the vehicle  10 . The short-range communication unit  103  performs communication in a short range (a range allowing communication between the interior and exterior of the vehicle cabin), using a predetermined wireless communication standards. Examples of the communication standards to be used for the communication by the short-range communication unit  103  include Bluetooth (R), Low Energy standards, Near Field Communication (NFC), Ultra Wide Band (UWB), and WiFi (R). 
     The control unit  104  is a computer that performs a process for performing the short-range wireless communication with the portable terminal  200 , a process for authenticating the portable terminal  200 , a process for transmitting a command signal to the control device  300 , and the like. For example, the control unit  104  is constituted by a microcomputer. 
     The control unit  104  has a function to control the LF receiver  101 , the RF transmitter  102  and the short-range communication unit  103 . Furthermore, the control unit  104  authenticates authentication information contained in a control request that is transmitted from the portable terminal  200  by the short-range wireless communication. Specifically, the control unit  104  determines whether the authentication information transmitted from the portable terminal  200  coincides with authentication information previously stored in a storage unit included in the control unit  104 . When the authentication succeeds, the control unit  104  transmits a command signal corresponding to a control request received from the portable terminal  200 , to the control device  300  through the RF transmitter  102 . Specifically, when the control request received from the portable terminal  200  is a locking request, the control unit  104  transmits the locking signal to the control device  300 . When the control request received from the portable terminal  200  is an unlocking request, the control unit  104  transmits the unlocking signal and the engine start permission signal to the control device  300 . 
     At this time, the key unit  100  transmits the key ID to the control device  300  together with the command signal. The key ID may be previously stored in the key unit  100  as a plain text, or may be stored while being encrypted by a code specific to the portable terminal  200 . In the case where the key ID is stored while being encrypted, the encrypted key ID may be decrypted by the authentication information transmitted from the portable terminal  200 , and the original key ID may be obtained. 
     Next, the portable terminal  200  will be described. For example, the portable terminal  200  is a small-size computer such as a smart phone, a cellular phone, a tablet terminal, a personal information terminal, and a wearable computer (a smart watch or the like). The portable terminal  200  is configured to include a short-range communication unit  201 , a communication unit  202 , a terminal-to-terminal communication unit  205 , a control unit  203 , and an input-output unit  204 . 
     The short-range communication unit  201  is a device that performs communication with the key unit  100  of the vehicle control device  11  in the same communication standards as for the short-range communication unit  103 . The communication unit  202  is a device that connects the portable terminal  200  to a network for performing communication with the server device  400 . The communication unit  202  can perform the communication with the server device  400  via the network, using a mobile communication service such as 3G and LTE, for example. The terminal-to-terminal communication unit  205  is means for performing communication with a different portable terminal. The terminal-to-terminal communication unit  205  may be a device that performs short-range wireless communication with the different portable terminal in the same communication standards as for the short-range communication unit  201 . Similarly to the communication unit  202 , the terminal-to-terminal communication unit  205  may be a device that performs the communication with the different portable terminal via a network. 
     The control unit  203  is a computer that controls the portable terminal  200 . For example, the control unit  203  is constituted by a microcomputer. The control unit  203  controls the short-range communication unit  201 , the communication unit  202  and the terminal-to-terminal communication unit  205 , in response to an input operation to the input-output unit  204  by a user. For example, the control unit  203  performs a process of requesting the delivery of the authentication information corresponding to the vehicle  10  to the server device  400  and receiving the delivered authentication information, through the communication unit  202 . The authentication information received from the server device  400  is stored in a storage unit included in the control unit  203 . Further, the control unit  203  performs a process of generating a control request corresponding to the input operation by the user and transmitting the control request to the key unit  100  through the short-range communication unit  201  together with the authentication information stored in the storage unit. Further, the control unit  203  transmits the authentication information received from the server device  400 , to the different portable terminal through the terminal-to-terminal communication unit  205 . A transfer of the authentication information between the portable terminals through the terminal-to-terminal communication unit  205  will be described later in detail. 
     The input-output unit  204  functions as means for accepting the input operation performed by the user and further presenting information to the user. Specifically, the input-output unit  204  is configured to include a touch panel display and control means for the touch panel display. The input-output unit  204  may include a hardware switch and the like that is operated by the user. 
     Behavior of Key System 
     Here, a behavior of the key system when the user controls the vehicle  10  using the portable terminal  200  will be described with an example in which the door of the vehicle  10  is unlocked.  FIG.  3    is a diagram showing a flow of processes and data when the door of the vehicle  10  is unlocked. 
     When the user performs, to the portable terminal  200 , an operation for unlocking the door of the vehicle  10 , the portable terminal  200  transmits the unlocking request and the authentication information to the key unit  100  of the vehicle control device  11  (S 101 ). Then, the key unit  100  performs an authentication process based on the authentication information received from the portable terminal  200  (S 102 ). When the authentication of the authentication information succeeds, the key unit  100  transmits the key ID to the control device  300 , together with the unlocking signal and the engine start permission signal (S 103 ). Then, the control device  300  performs an authentication process based on the key ID received from the key unit  100  (S 104 ). When the authentication of the key ID succeeds, the control device  300  performs an unlocking control of unlocking the door of the vehicle  10  and an engine start permission control of putting the engine ECU  305  into the engine start allowing state (S 105 ). 
     In the embodiment, the locking-unlocking control and the engine start permission control correspond to the “predetermined control”. However, the “predetermined control” is not limited to these controls, and may include another control that is allowed to be performed when the vehicle control device  11  receives the authentication information from the portable terminal  200 . 
     Sharing of Authentication Information 
     In the above-described key system, when the user receives the authentication information corresponding to the vehicle  10  from the server device  400  with the user&#39;s own portable terminal (hereinafter, also referred to as a “user terminal”), the user terminal can be used as a key for the vehicle  10 . On this occasion, in the case where the user shares the vehicle  10  with a third party or lends the vehicle  10  to the third party, the user needs to lend the user terminal itself to the third party at the time of the utilization of the vehicle  10  by the third party, if only the user terminal has the authentication information and a portable terminal possessed by the third party (hereinafter, also referred to as a “third-party terminal”) does not have the authentication information. However, the situation in which the user lends the user terminal itself to the third party significantly decreases convenience. Hence, in the key system according to the embodiment, the authentication information can be shared by the user terminal and the third-party terminal. 
       FIG.  4    is a diagram for describing a transfer of the authentication information from the user terminal to the third-party terminal according to the embodiment. In  FIG.  4   , reference numeral  200   a  denotes the user terminal, and reference numeral  200   b  denotes the third-party terminal. The user terminal  200   a  and the third-party terminal  200   b  have the same configuration as the portable terminal  200  shown in  FIG.  2   . Therefore, the third-party terminal  200   b  can also perform the short-range wireless communication with the vehicle control device  11  of the vehicle  10 . Accordingly, when the third-party terminal  200   b  acquires the authentication information corresponding to the vehicle  10 , the third party can use the third-party terminal  200   b  as a key for the vehicle  10 . Hence, in the embodiment, the user terminal  200   a  acquires authentication information for lending from the server device  400 , and the user terminal  200   a  transfers the authentication information to the third-party terminal  200   b.    
     Here, a configuration of the server device  400  will be described. The server device  400  is a computer that includes a microprocessor, a storage device, an input-output device and a communication device, and the microprocessor executes programs to realize the following functions. However, some or all of the functions may be realized by hardware circuits such as ASICs and FPGAs. Further, the server device  400  does not need to be realized by a single computer, or may be realized by a plurality of computers in cooperation. 
     As shown in  FIG.  4   , the server device  400  includes a request receiving unit  401 , an information generation unit  402 , an information transmitting unit  403 , and a management unit  404 . The request receiving unit  401  is means for receiving the delivery request for the authentication information that is transmitted from the user terminal  200   a . The request receiving unit  401  receives the delivery request transmitted from the user terminal  200   a , via the network. 
     The information generation unit  402  is means for generating the authentication information corresponding to the delivery request from the user terminal  200   a  that is received by the request receiving unit  401 . The information generation unit  402  generates the authentication information associated with the vehicle  10  that is a utilization object. The information transmitting unit  403  is means for transmitting the authentication information generated by the information generation unit  402 , to the user terminal  200   a . The information transmitting unit  403  transmits the authentication information to the user terminal  200   a  via the network. The management unit  404  is means for managing delivery situation of the authentication information from the server device  400 . For example, the management unit  404  stores the authentication information to be delivered and the user terminal as the delivery destination, in association with each other. 
     Here, in the case where the user shares the vehicle  10  with the third party or lends the vehicle  10  to the third party, the user, by operating the user terminal  200   a , transmits the delivery request about the authentication information for lending from the user terminal  200   a  to the server device  400 . In the server device  400 , when the request receiving unit  401  receives the delivery request about the authentication information for lending, the information generation unit  402  adds transfer allowing information (DR) I 2  (second information) to authentication information I 1  associated with the vehicle  10 . Then, the information transmitting unit  403  transmits the authentication information I 1  to which the transfer allowing information I 2  has been added, to the user terminal  200   a . Here, the transfer allowing information I 2  is information that allows the authentication information I 1  to be transferred between the user terminal  200   a  and the third-party terminal  200   b  without the server device  400 . That is, by the addition of the transfer allowing information I 2  to the authentication information I 1 , the authentication information I 1  is allowed to be transmitted from the user terminal  200   a  to the third-party terminal  200   b . In other words, when the user terminal  200   a  receives the authentication information I 1  to which the transfer allowing information I 2  has not been added, the user terminal  200   a  cannot transmit the authentication information I 1  to the third-party terminal  200   b . When the server device  400  delivers the authentication information to which the transfer allowing information has been added, the management unit  404 , similarly, stores the authentication information and the user terminal as the delivery destination, in association with each other. 
     When the user terminal  200   a  receives the authentication information I 1  to which the transfer allowing information I 2  has been added, the user terminal  200   a  transmits the authentication information I 1  to the third-party terminal  200   b  through the terminal-to-terminal communication unit  205   a , in response to the input operation by the user. Then, the third-party terminal  200   b  stores the authentication information I 1  received from the user terminal  200   a  through the terminal-to-terminal communication unit  205   b , in the storage unit included in the control unit  203 . Thereby, the authentication information I 1  associated with the vehicle  10  can be shared by the user terminal  200   a  and the third-party terminal  200   b . As a result, the third party can use the third-party terminal  200   b  as a key for the vehicle  10 . The transfer allowing information I 2  is not added to the authentication information I 1  that is transmitted from the user terminal  200   a  to the third-party terminal  200   b . Thereby, the authentication information I 1  cannot be transmitted from the third-party terminal  200   b  to a different portable terminal. Therefore, it is possible to prevent the authentication information from being sublet. 
       FIG.  5    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal  200   a  to the third-party terminal  200   b . When the user performs an operation for requesting the user terminal  200   a  to acquire the authentication information for lending through the input-output unit  204 , the user terminal  200   a  transmits the delivery request about the authentication information for lending to the server device  400  (S 201 ). When the server device  400  receives the delivery request, in the server device  400  the information generation unit  402  generates the authentication information associated with the vehicle  10 , and adds the transfer allowing information (DR) to the authentication information (S 202 ). Then, the server device  400  transmits the authentication information to which the transfer allowing information has been added, to the user terminal  200   a  (S 203 ). Thereafter, the user performs an operation for transmitting the authentication information to the third-party terminal  200   b  through the input-output unit  204 , to the user terminal  200   a , so that the user terminal  200   a  transmits the authentication information to the third-party terminal  200   b  (S 204 ). 
     The third-party terminal  200   b  stores the authentication information received from the user terminal  200   a . Then, when the third party controls the vehicle  10  using the third-party terminal  200   b , the authentication information stored in the third-party terminal  200   b  is transmitted to the vehicle control device  11 . Thereby, the key unit  100  and the control device  300  of the vehicle control device  11  behave as in the case of receiving the authentication information from the user terminal  200   a.    
     As described above, in the embodiment, the authentication information for lending is delivered from the server device  400  to the user terminal  200   a , and the authentication information is transmitted from the user terminal  200   a  to the third-party terminal  200   b . That is, the authentication information transferred to the third-party terminal  200   b  is also the information delivered from the server device  400 . Therefore, it is possible to avoid the authentication information from being generated in the user terminal  200   a  with no restriction, and to avoid the generated authentication information from being transferred to the third-party terminal  200   b . Accordingly, the authentication information can be shared by the user terminal  200   a  and the third-party terminal  200   b  while the security is ensured. Further, since the authentication information for lending is delivered from the server device  400 , the authentication information to be transferred from the user terminal  200   a  to the third-party terminal  200   b  can be recorded or managed on the server device  400  side. 
     Modification 
     In the first embodiment, the vehicle control device  11  includes the key unit  100 . Further, the authentication information is transmitted from the portable terminal  200  to the key unit  100 , and then the key ID is transmitted from the key unit  100  to the control device  300 . However, a configuration in which the key unit  100  does not intervene between the portable terminal  200  and the control device  300  can be employed. In this case, the key ID is delivered from the server device  400  to the portable terminal  200 . Then, the key ID is transmitted from the portable terminal  200  to the control device  300 . At this time, the key ID corresponds to the “key information”. Also in the case of employing such a configuration, the key ID can be shared by the user terminal  200   a  and the third-party terminal  200   b  while the security is ensured, by adding the transfer allowing information that allows the key ID to be transferred between the user terminal  200   a  and the third-party terminal  200   b  without the server device  400 , to the key ID to be delivered from the server device  400 . 
     Second Embodiment 
     The overview of the key system according to the embodiment is the same as that according to the first embodiment. In the embodiment, it is possible to restrict the control that the third party is allowed to perform to the vehicle using the third-party terminal. For the embodiment, different points from the first embodiment will be mainly described below. 
     Operation of User Terminal 
     When the user shares the vehicle  10  with the third party, the user sometimes permits the third party to access the vehicle cabin (or a luggage room) of the vehicle  10  (that is, the user permits the third party to lock and unlock the door of the vehicle  10 ), but does not permit the third party to drive the vehicle  10 . In the embodiment, in such a case, the user demands to add function restriction information (third information) to the authentication information for lending, at a time when the user requests the delivery of the authentication information for lending to the server device  400 . 
       FIG.  6    is a diagram showing an operation screen  2040  of a touch panel display that is included in an input-output unit  204   a  of a user terminal  200   a  and that is operated when the user requests the delivery of the authentication information for lending to the server device  400 . The operation screen  2040  includes a “PERMIT DRIVING” button  2041  and a “NOT PERMIT DRIVING” button  2042 , which are operation buttons (UI elements). 
     In the case where the user permits the third party to drive the vehicle  10 , the user selects the “PERMIT DRIVING” button  2041  on the operation screen  2040 . In the case where the “PERMIT DRIVING” button  2041  is selected, the addition of the function restriction information to the authentication information for lending is not demanded to the server device  400 . On the other hand, in the case where the user does not permit the third party to drive the vehicle  10 , the user selects the “NOT PERMIT DRIVING” button  2042  on the operation screen  2040 . In the case where the “NOT PERMIT DRIVING” button  2042  is selected, the addition of the function restriction information to the authentication information for lending is demanded to the server device  400 .  FIG.  6    illustrates a state in which a checkbox of the “NOT PERMIT DRIVING” button  2042  has been checked because the user selected the “NOT PERMIT DRIVING” button  2042 . 
     Sharing of Authentication Information 
       FIG.  7    is a diagram for describing a transfer of the authentication information from the user terminal  200   a  to the third-party terminal  200   b  in the key system according to the embodiment in the case where the user does not permit the third party to drive the vehicle (that is, in the case where the user selects the “NOT PERMIT DRIVING” button  2042  on the operation screen  2040  of the user terminal  200   a  shown in  FIG.  6   ).  FIG.  8    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal  200   a  to the third-party terminal  200   b  in that case. 
     In the case where the user selects the “NOT PERMIT DRIVING” button  2042  on the operation screen  2040  of the user terminal  200   a , the user terminal  200   a  transmits the function restriction request about the authentication information for lending to the server device  400 , together with the delivery request about the authentication information for lending (S 301  in  FIG.  8   ). In the server device  400 , when the request receiving unit  401  receives the requests, the information generation unit  402  generates the authentication information I 1  associated with the vehicle  10 . Furthermore, the information generation unit  402  adds function restriction information (RF) I 3  to the authentication information I 1 , together with the transfer allowing information (DR) I 2  (S 302  in  FIG.  8   ). 
     At this time, the function restriction information I 3  is generated based on the function restriction request received from the user terminal  200   a . That is, a restriction content to be restricted by the function restriction information I 3  is set depending on a request content of the function restriction request. Here, since the “NOT PERMIT DRIVING” button  2042  is selected on the operation screen  2040  of the user terminal  200   a , the function restriction request is transmitted from the user terminal  200   a . That is, in this function restriction request, the user requests that the engine start permission control be not executed in the vehicle control device  11  of the vehicle  10 . Therefore, the function restriction information I 3  is generated as information for restricting the execution of the engine start permission control by the vehicle control device  11  of the vehicle  10 . A behavior of the vehicle control device  11  of the vehicle  10  when the vehicle control device  11  receives the authentication information I 1  to which the function restriction information I 3  has been added will be described later in detail. 
     Then, the information transmitting unit  403  of the server device  400  transmits the authentication information I 1  to which the transfer allowing information I 2  and the function restriction information I 3  have been added, to the user terminal  200   a  (S 303  in  FIG.  8   ). Then, when the user terminal  200   a  receives the authentication information I 1  to which the transfer allowing information I 2  and the function restriction information I 3  have been added, the user terminal  200   a  transmits the authentication information I 1  to which the function restriction information I 3  has been added, to the third-party terminal  200   b  through the terminal-to-terminal communication unit  205   a , in response to the input operation by the user (S 304  in  FIG.  8   ). The third-party terminal  200   b  stores the authentication information I 1  to which the function restriction information I 3  has been added and that has been received from the user terminal  200   a  through the terminal-to-terminal communication unit  205   b , in the storage unit included in the control unit  203 . 
     Behavior of Key System 
     Next, a behavior of the key system in the embodiment when the third party unlocks the door of the vehicle  10  using the third-party terminal  200   b  having the authentication information I 1  to which the function restriction information I 3  has been added will be described.  FIG.  9    is a diagram showing a flow of processes and data when the door of the vehicle  10  is unlocked. 
     When the third party performs, to the third-party terminal  200   b , the operation for unlocking the door of the vehicle  10 , the third-party terminal  200   b  transmits the authentication information to which the function restriction information (RF) has been added, to the key unit  100  of the vehicle control device  11 , together with the unlocking request (S 401 ). Then, the key unit  100  performs the authentication process based on the authentication information received from the third-party terminal  200   b  (S 402 ). The authentication process itself of S 402  is the same as the authentication process of S 102  in  FIG.  3   . However, in the case where the function restriction information has been added to the authentication information, the engine start permission signal is not transmitted from the key unit  100 , even when the authentication of the authentication information succeeds in the authentication process of S 402 . That is, together with the key ID, only the unlocking signal is transmitted from the key unit  100  to the control device  300  (S 403 ). Then, the control device  300  receives the key ID and the unlocking signal, and performs the authentication process based on the key ID (S 404 ). When the authentication of the key ID succeeds, the control device  300  performs the unlocking control of unlocking the door of the vehicle  10  (S 405 ). Since the control device  300  does not receive the engine start permission signal, the control device  300  does not perform the engine start permission control of putting the engine ECU  305  into the engine start allowing state. 
     As described above, when the function restriction information is added to the authentication information that is transmitted from the third-party terminal  200   b  to the key unit  100  of the vehicle control device  11 , the engine ECU  305  is not put into the engine start allowing state. Therefore, the third party possessing the third-party terminal  200   b  cannot start the engine  13  of the vehicle  10 , although the third party can lock and unlock the door of the vehicle  10 . That is, the third party cannot drive the vehicle  10  using the third-party terminal  200   b.    
     In this way, when the function restriction information is added to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b , it is possible to restrict the control that is allowed to be performed to the vehicle  10  by the vehicle control device  11  when the authentication information is transmitted from the third-party terminal  200   b  to the vehicle control device  11 . That is, it is possible to restrict the control that the third party is allowed to perform to the vehicle  10  using the third-party terminal  200   b . In the above description, the control that is restricted by adding the function restriction information to the authentication information is the engine start permission control, but another control that is allowed to be performed when the vehicle control device  11  receives the authentication information from the portable terminal may be restricted. 
     First Modification 
     In the second embodiment, the server device  400  adds the function restriction information to the authentication information for lending, based on the demand that is transmitted from the user terminal  200   a . Then, the authentication information to which the function restriction information has been added is transmitted from the server device  400  to the user terminal  200   a . However, the addition of the function restriction information to the authentication information for lending may be performed on the user terminal  200   a  side. Also in this case, the authentication information for lending to which the transfer allowing information has been added is transmitted from the server device  400  to the user terminal  200   a , in response to the request transmitted from the user terminal  200   a . Then, the function restriction information is added to the authentication information for lending in the user terminal  200   a , in response to an input operation performed to the operation screen  2040  of the user terminal  200   a  shown in  FIG.  6    by the user. The addition of the function restriction information to the authentication information for lending is performed by the control unit  203 . Then, similarly to the second embodiment, the user terminal  200   a  transmits the authentication information to which the function restriction information has been added, to the third-party terminal  200   b . Also in this case, similarly to the second embodiment, it is possible to restrict the control that the third party is allowed to perform to the vehicle  10  using the third-party terminal  200   b.    
     Second Modification 
     The addition of the function restriction information to the authentication information for lending does not always need to be performed based on the demand from the user. That is, the server device  400  may automatically add, to the authentication information, the function restriction information in which the function restriction content is previously determined, while adding the transfer allowing information, when the server device  400  delivers the authentication information for lending. 
     Third Embodiment 
     The overview of the key system according to the embodiment is the same as that according to the first embodiment. In the embodiment, it is possible to restrict a period or region in which the third party is allowed to utilize the vehicle using the third-party terminal. For the embodiment, different points from the first embodiment will be mainly described below. 
     Operation of User Terminal 
     When the user shares the vehicle  10  with the third party or lends the vehicle  10  to the third party, the user sometimes restricts the period or region in which the third party is allowed to utilize the vehicle  10 . In the embodiment, in such a case, the user demands to add use restriction information (fourth information) to the authentication information for lending, at the time when the user requests the delivery of the authentication information for lending to the server device  400 . Here, the use restriction information may be period restriction information for restricting the period in which the third party is allowed to utilize the vehicle  10 , or may be region restriction information for restricting the region in which the third party is allowed to utilize the vehicle  10 . Further, the use restriction information may contain both the period restriction information and the region restriction information. 
       FIG.  10    and  FIG.  11    are diagrams showing operation screens of a touch panel display that is included in an input-output unit  204   a  of a user terminal  200   a  and that is operated when the user requests the delivery of the authentication information for lending to the server device  400 .  FIG.  10    shows an operation screen  2043  when the user demands the addition of the period restriction information as the use restriction information. The operation screen  2043  contains an operation button (UI element)  2044  for inputting an expiration date. The expiration date to be input here is a time limit by which the authentication information can be validly used by the third-party terminal  200   b  after the authentication information is transferred from the user terminal  200   a  to the third-party terminal  200   b . A valid use period about the authentication information for lending that is restricted by the period restriction information is set based on the expiration date input on the operation screen  2043 . That is, the period restriction information is information that restricts the use period in which the third-party terminal  200   b  is allowed to validly use the authentication information. A valid use period about the authentication information for lending may be directly input on the operation screen  2043 , instead of the expiration date about the authentication information for lending. Further, the number of times of use in which the third-party terminal  200   b  is allowed to validly use the authentication information may be restricted instead of the use period in which the third-party terminal  200   b  is allowed to validly use the authentication information. 
       FIG.  11    shows an operation screen  2045  when the user demands the addition of the region restriction information as the use restriction information. The operation screen  2045  contains an operation button (UI element)  2046  for inputting a valid region. On the operation screen  2045 , the valid region is input by being selected from a plurality of regions (regions A, B, C, D, . . . ) previously set. The input method for the valid region is not limited to such a method, and for example, the valid region may be set on a map that is displayed on the screen. The valid use region about the authentication information for lending that is restricted by the region restriction information is set based on the valid region input on the operation screen  2045 . That is, the region restriction information is information that restricts the region in which the third-party terminal  200   b  is allowed to validly use the authentication information. 
     Sharing of Authentication Information 
       FIG.  12    is a diagram for describing a transfer of the authentication information from the user terminal  200   a  to the third-party terminal  200   b  in the key system according to the embodiment in the case where the user provides the restriction about the utilization of the vehicle  10  by the third party (that is, in the case where the expiration date is input on the operation screen  2043  of the user terminal  200   a  shown in  FIG.  10    and/or in the case where the valid region is input on the operation screen  2045  of the user terminal  200   a  shown in  FIG.  11   ).  FIG.  13    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal  200   a  to the third-party terminal  200   b  in that case. 
     In the case where the user inputs the expiration date on the operation screen  2043  and/or in the case where the user inputs the valid region on the operation screen  2045 , the user terminal  200   a  transmits the user restriction request about the authentication information for lending to the server device  400 , together with the delivery request about the authentication information for lending (S 501  in  FIG.  13   ). In the server device  400 , when the request receiving unit  401  receives the requests, the information generation unit  402  generates the authentication information I 1  associated with the vehicle  10 . Furthermore, the information generation unit  402  adds the use restriction information (RU) I 4  to the authentication information I 1 , together with the transfer allowing information (DR) I 2  (S 502  in  FIG.  13   ). 
     At this time, the use restriction information I 4  is generated based on the use restriction request received from the user terminal  200   a . That is, a restriction content to be restricted by the use restriction information I 4  is set depending on a request content of the use restriction request. Here, since the expiration date is input on the operation screen  2043  of the user terminal  200   a  shown in  FIG.  10    and/or the valid region is input on the operation screen  2045  of the user terminal  200   a  shown in  FIG.  11   , the use restriction request is transmitted from the user terminal  200   a . That is, in this use restriction request, the user requests that the valid use period and/or valid use region set as described above be provided about the authentication information for lending. Therefore, the use restriction information I 4  is generated based on the valid use period and/or valid use region set as described above. 
     Then, the information transmitting unit  403  of the server device  400  transmits the authentication information I 1  to which the transfer allowing information I 2  and the use restriction information I 4  have been added, to the user terminal  200   a  (S 503  in  FIG.  13   ). When the user terminal  200   a  receives the authentication information I 1  to which the transfer allowing information I 2  and the use restriction information I 4  have been added, the user terminal  200   a  transmits the authentication information I 1  to which the use restriction information I 4  has been added, to the third-party terminal  200   b  through the terminal-to-terminal communication unit  205   a , in response to the input operation by the user (S 504  in  FIG.  13   ). The third-party terminal  200   b  stores the authentication information I 1  to which the use restriction information I 4  has been added and that has been received from the user terminal  200   a  through the terminal-to-terminal communication unit  205   b , in the storage unit included in the control unit  203 . 
     Behavior of Key System 
     When the third-party terminal  200   b  receives the authentication information to which the use restriction information has been added, the third party is allowed to utilize the vehicle  10  using the third-party terminal  200   b . That is, by transmitting the authentication information from the third-party terminal  200   b  to the vehicle control device  11  of the vehicle  10  together with the control request, it is possible to make the vehicle control device  11  perform a control corresponding to the control request. 
     However, in the case where the use restriction information contains the period restriction information, the authentication information stored in the control unit  203  of the third-party terminal  200   b  expires when the set valid use period elapses. Therefore, when the valid use period elapses, the third party is not allowed to utilize the vehicle  10  using the third-party terminal  200   b . The third-party terminal  200   b  may notify the third party of the elapse of the set valid use period, before the valid use period elapses. Further, in the case where the use restriction information contains the information that restricts the number of times of use in which the authentication information is allowed to be validly used, the authentication information stored in the control unit  203  of the third-party terminal  200   b  expires when the authentication information is transmitted from the third-party terminal  200   b  to the vehicle control device of the vehicle  10  to the number of times of valid use set. 
     Further, in the case where the use restriction information contains the region restriction information, the third-party terminal  200   b  is not allowed to transmit the authentication information to the vehicle control device  11 , when the third party possessing the third-party terminal  200   b  drives to move the vehicle  10  to a place outside the set valid use region. Therefore, in the place outside the valid use region, the third party is not allowed to utilize the vehicle  10  using the third-party terminal  200   b . The position of the third-party terminal  200   b  can be acquired by a positional information acquiring device such as a GPS that is mounted on the third-party terminal  200   b  or the vehicle  10 . Then, whether the third-party terminal  200   b  and the vehicle  10  exist in the valid use region can be determined based on the acquired positional information. When the third-party terminal  200   b  and the vehicle  10  are expected to move to the place outside the valid use region or have moved to the place outside the valid use region, the third-party terminal  200   b  may notify the third party of that effect. 
     As described above, it is possible to restrict the use of the authentication information by the third-party terminal  200   b , by adding the use restriction information to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b . That is, it is possible to provide the restriction about the utilization of the vehicle  10  when the third party transmits the authentication information from the third-party terminal  200   b  to the vehicle control device  11 . 
     First Modification 
     Together with the use restriction information, the function restriction information described in the second embodiment may be added to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b.    
     Second Modification 
     In the second embodiment, the server device  400  adds the use restriction information to the authentication information for lending, based on the demand that is transmitted from the user terminal  200   a . Then, the server device  400  transmits the authentication information to which the use restriction information has been added, to the user terminal  200   a . However, the addition of the use restriction information to the authentication information for lending may be performed on the user terminal  200   a  side. Also in this case, the server device  400  transmits the authentication information for lending to which the transfer allowing information has been added, to the user terminal  200   a , in response to the request that is transmitted from the user terminal  200   a . Then, in the user terminal  200   a , the use restriction information is added to the authentication information, in response to the input operation performed by the user on the operation screens  2043 ,  2045  of the user terminal  200   a  shown in  FIG.  10    and/or  FIG.  11   . The addition of the use restriction information to the authentication information is performed by the control unit  203 . Then, similarly to the third embodiment, the user terminal  200   a  transmits the authentication information to which the use restriction information has been added, to the third-party terminal  200   b . Also in this case, similarly to the third embodiment, it is possible to provide the restriction about the utilization of the vehicle  10  when the third party transmits the authentication information from the third-party terminal  200   b  to the vehicle control device  11 . 
     Third Modification 
     The addition of the use restriction information to the authentication information for lending does not always need to be performed based on the demand from the user. That is, the server device  400  may automatically add, to the authentication information, the use restriction information in which the use restriction content is previously determined, while adding the transfer allowing information, when the server device  400  delivers the authentication information for lending. 
     Fourth Embodiment 
     The overview of the key system according to the embodiment is the same as that according to the first embodiment. In the embodiment, it is possible to restrict the range of the third party with which the user shares the authentication information, by restricting the third-party terminal as a destination to which the authentication information is transmitted from the user terminal, only to a particular third-party terminal belonging to a particular group. For the embodiment, different points from the first embodiment will be mainly described below. 
     Operation of User Terminal 
     By restricting the third-party terminal to which the authentication information is allowed to be transmitted from the user terminal, only to the particular third-party terminal, it is possible to avoid the authentication information from being transmitted to a terminal to which the user does not intend to transmit the authentication information. Hence, in the embodiment, the user demands to add sharer restriction information (fifth information) to the authentication information for lending, at the time when the user requests the delivery of the authentication information for lending to the server device  400 . 
       FIG.  14    is a diagram showing an operation screen  2047  of a touch panel display that is included in an input-output unit  204   a  of a user terminal  200   a  and that is operated when the user requests the delivery of the authentication information for lending to the server device  400 . The operation screen  2047  includes an operation button (UI element)  2048  for inputting a group with which the authentication information is shared. On the operation screen  2047 , a particular group is input by being selected from a plurality of groups (groups A, B, C, D, . . . ) previously set. Here, in the user terminal  200   a , a plurality of candidates that can be a sharer of the authentication information is registered in a registration unit included in the control unit  203 , while being grouped into the plurality of groups (groups A, B, C, D, . . . ). That is, the plurality of third-party terminals corresponding to the candidates is registered while being grouped into the plurality of groups. In the embodiment, the registration unit included in the control unit  203  corresponds to the “registration unit”. On the operation screen  2047 , the particular group is selected from the plurality of groups registered in the registration unit of the control unit  203 .  FIG.  14    illustrates a state in which the group A has been selected as the particular group. The setting method for the particular group is not limited to such a method, and for example, the particular group may be set by selecting a candidate from a name list (an address book or the like) in a predetermined application included in the user terminal  200   a.    
     Sharing of Authentication Information 
       FIG.  15    is a diagram for describing a transfer of the authentication information from the user terminal  200   a  to the third-party terminal  200   b  in the key system according to the embodiment in the case where the user restricts the sharer of the authentication information only to the particular third-party terminal belonging to the particular group (that is, in the case where the user inputs the particular group on the operation screen  2047  of the user terminal  200   a  shown in  FIG.  14   ).  FIG.  16    is a diagram showing a flow of processes and data when the authentication information is transferred from the user terminal  200   a  to the third-party terminal  200   b  in that case. In the following description, it is assumed that the group A is selected as the particular group on the operation screen  2047  of the user terminal  200   a  shown in  FIG.  14   . 
     In the case where the user inputs the particular group (the group A is selected in this example) on the operation screen  2047 , the user terminal  200   a  transmits information about each particular third-particular terminal belonging to the group A selected as the particular group (hereinafter, also referred to as “A terminal ID”), to the server device  400 , together with the delivery request about the authentication information for lending (S 601  in  FIG.  16   ). In the server device  400 , when the request receiving unit  401  receives the delivery request about the authentication information for lending and the A terminal ID, the information generation unit  402  generates the authentication information I 1  associated with the vehicle  10 . Furthermore, the information generation unit  402  adds sharer restriction information (RG) I 5  to the authentication information I 1 , together with the transfer allowing information (DR) I 2  (S 602  in  FIG.  16   ). The sharer restriction information I 5  to be added at this time is information that is generated in association with the A terminal ID received from the user terminal  200   a.    
     Then, the information transmitting unit  403  of the server device  400  transmits the authentication information I 1  to which the transfer allowing information I 2  and the sharer restriction information I 5  have been added, to the user terminal  200   a  (S 603  in  FIG.  16   ). Since the user terminal  200   a  receives the authentication information I 1  to which the sharer restriction information I 5  has been added, the destination to which the authentication information I 1  is allowed to be transmitted is restricted only to the particular third-party terminal belonging to the group A. That is, when the user terminal  200   a  receives the authentication information I 1  to which the sharer restriction information I 5  has been added, the user terminal  200   a  is not allowed to transmit the authentication information I 1  to the third-party terminal not belonging to the group A, even when the transfer allowing information I 2  has been added to the authentication information I 1 . Then, in response to the input operation by the user, the user terminal  200   a  transmits the authentication information I 1  to which the sharer restriction information I 5  has been added, to the third-party terminal  200   b  belonging to the group A, through the terminal-to-terminal communication unit  205   a  (S 604  in  FIG.  16   ). The third-party terminal not belonging to the group A may be configured such that when the user terminal  200   a  transmits the authentication information I 1  to which the sharer restriction information I 5  has been added, the third-party terminal not belonging to the group A cannot receive the authentication information I 1 . 
     First Modification 
     The function restriction information described in the second embodiment and/or the use restriction information described in the third embodiment may be added to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b  belonging to the particular group. 
     Second Modification 
     In the fourth embodiment, the server device  400  adds the sharer restriction information to the authentication information for lending, based on the demand that is transmitted from the user terminal  200   a . Then, the server device  400  transmits the authentication information to which the sharer restriction information has been added, to the user terminal  200   a . However, the addition of the sharer restriction information to the authentication information for lending may be performed on the user terminal  200   a  side. Also in this case, the server device  400  transmits the authentication information for lending to which the transfer allowing information has been added, to the user terminal  200   a , in response to the request that is transmitted from the user terminal  200   a . Then, in the user terminal  200   a , the sharer restriction information is added to the authentication information, in response to the input operation performed by the user on the operation screen  2047  of the user terminal  200   a  shown in  FIG.  14   . The addition of the sharer restriction information to the authentication information is performed by the control unit  203 . Also in this case, similarly to the fourth embodiment, it is possible to restrict the third-party terminal  200   b  to which the authentication information is allowed to be transmitted from the user terminal  200   a , only to the particular third-party terminal. 
     Third Modification 
     The addition of the sharer restriction information to the authentication information for lending does not always need to be performed based on the demand from the user. That is, the server device  400  may automatically add, to the authentication information, the sharer restriction information in which the particular third-party terminal is previously determined, while adding the transfer allowing information, when the server device  400  delivers the authentication information for lending. 
     Fifth Embodiment 
     The overview of the key system according to the embodiment is the same as that according to the first embodiment. In the embodiment, similarly to the fourth embodiment, in the user terminal  200   a , a plurality of candidates that can be a sharer of the authentication information is registered in a registration unit included in the control unit  203 , while being grouped into a plurality of groups. Further, in the key system according to the embodiment, similarly to the second embodiment, the function restriction information can be added to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b . Furthermore, in the key system according to the embodiment, similarly to the third embodiment, the use restriction information can be added to the authentication information that is transferred from the user terminal  200   a  to the third-party terminal  200   b.    
     In the embodiment, when the authentication information is shared by the user terminal  200   a  and the third-party terminal  200   b , the restriction content for the function restriction information and/or use restriction information to be added to the authentication information is set for each of the above-described groups (the groups constituted by a plurality of the third-party terminals) registered in the registration unit included in the control unit  203  of the user terminal  200   a . Specifically, the user terminal  200   a  sets the restriction content in the function restriction request for each of the groups. Then, when the user terminal  200   a  transmits the delivery request about the authentication information for lending to the server device  400 , the user terminal  200   a  transmits together the function restriction request corresponding to a group to which the third-party terminal as the destination of the authentication information for lending belongs. Thereby, in the server device  400 , the function restriction information corresponding to the function restriction request set for each of the groups is added to the authentication information for lending. 
     Further, the user terminal  200   a  sets the restriction content in the use restriction request for each of the groups. Then, when the user terminal  200   a  transmits the delivery request about the authentication information for lending to the server device  400 , the user terminal  200   a  transmits together the use restriction request corresponding to the group to which the third-party terminal as the destination of the authentication information for lending belongs. Thereby, in the server device  400 , the use restriction information corresponding to the use restriction request set for each of the groups is added to the authentication information for lending. 
     As described above, it is possible to transmit, to the third-party terminal, the authentication information to which the function restriction information and/or use restriction information with the restriction content corresponding to the group to which the third-party terminal as the sharer of the authentication information belongs have been added. 
     Modification 
     Also in the case of adding, to the authentication information for lending, the function restriction information and/or use restriction information with the restriction content corresponding to the group to which the third-party terminal as the sharer of the authentication information belongs as described in the fifth embodiment, the addition of the function restriction information and/or use restriction information to the authentication information for lending may be performed on the user terminal  200   a  side, instead of the server device  400  side. 
     Other Embodiments 
     In the above description, the object to be controlled when the authentication information is transmitted from the portable terminal to the control device is a vehicle. However, the above system can be applied to an object other than the vehicle, for example, a facility (including a building and a house), an airplane, a ship and the like. By applying the above system, the user terminal and the third-party terminal can share the authentication information for making a control device equipped in the object other than the vehicle perform a predetermined control to the object. 
     In the above description, the information generation unit further adds the third information that is the information for restricting the predetermined control that is allowed to be performed to the object when the control device receives the first information, to the first information, when the information generation unit adds the second information to the first information. However, the third information to be added to the first information by the information generation unit may be information for additionally permitting a predetermined control that is allowed to be performed to the object when the control device receives the first information. Thereby, the predetermined control that is allowed to be performed to the object by the control device when the third-party terminal transmits the first information to the control device is additionally permitted. Accordingly, it is possible to additionally permit the predetermined control that is allowed to be performed to the object by the control device, when the third party utilizes the object using the third-party terminal. This modification is effective in the case where the predetermined control is previously restricted. 
     In the above case, the information generation unit may set a content that is included in the third information and that is additionally permitted in the predetermined control, based on a function permission request that is transmitted from the user terminal to the delivery device, and may add the third information to the first information. Thereby, when the user sets the content of the function permission request that is delivered from the user terminal to the delivery device, the user can determine the content to be additionally permitted in the predetermined control that is allowed to be performed to the object by the control device when the third party transmits the first information from the third-party terminal to the control device. 
     In the above case, the user terminal may further include a registration unit configured to register a plurality of the third-party terminals while grouping the plurality of the third-party terminals into a plurality of groups, and the user terminal may set the permission content in the function permission request for each of the groups and may transmit the function permission request to the delivery device. In this case, the information generation unit may add the third information corresponding to the function permission request set for each of the groups, to the first information. Thereby, for each of the groups, the user can set the content to be additionally permitted in the predetermined control that is allowed to be performed to the object by the control device when the first information is transmitted from the third-party terminal to the control device. 
     In the above description, the information generation unit further adds the fourth information that is information for restricting the use of the first information by the third-party terminal, to the first information, when the information generation unit adds the second information to the first information. However, the information generation unit may further add the fourth information that is information for additionally permitting the use of the first information by the third-party terminal, to the first information, when the information generation unit adds the second information to the first information. Then, when the user terminal receives the first information to which the second information and the fourth information have been added, from the delivery device, the user terminal may transmit the first information to which the fourth information has been added, from the terminal-to-terminal communication unit to the third-party terminal. Thereby, the third-party terminal receives the first information to which the fourth information has been added. Accordingly, it is possible to provide the additional permission about the utilization of the object when the third party transmits the first information from the third-party terminal to the control device. 
     In the above case, the information generation unit may set a content that is included in the fourth information and that is additionally permitted in the first information, based on a use permission request that is transmitted from the user terminal to the delivery device, and may add the fourth information to the first information. Thereby, when the user sets the content of the use permission request that is delivered from the user terminal to the delivery device, the user can determine the content to be additionally permitted about the utilization of the object when the third party transmits the first information from the third-party terminal to the control device. 
     Here, the fourth information may contain information for permitting the use period or the number of times of use in which the third-party terminal is allowed to validly use the first information. When the third-party terminal receives the first information to which the fourth information has been added, the third-party terminal transmits the first information to the control device, and thereby, the period or the number of times in which the control device is allowed to perform the predetermined control to the object is permitted. Accordingly, it is possible to additionally permit the period or the number of times in which the third party is allowed to utilize the object. Further, in the case where the object is a movable body such as a vehicle, the fourth information may contain information for permitting the region in which the third-party terminal is allowed to validly use the first information. When the third-party terminal receives the first information to which the fourth information has been added, the region in which the control device is allowed to perform the predetermined control to the movable body (object) when the first information is transmitted from the third-party terminal to the control device is additionally permitted. Accordingly, it is possible to additionally restrict the region in which the third party is allowed to utilize the movable body (object). 
     When the user terminal further includes the registration unit configured to register the plurality of third-party terminals while grouping the plurality of third-party terminals into the plurality of groups, the user terminal may set the permission content in the use permission request for each of the groups, and may transmit the use permission request to the delivery device. In this case, in the delivery device, the information generation unit adds the fourth information corresponding to the use permission request set for each of the groups, to the first information. Thereby, for each of the groups, the user can set the permission content about the utilization of the object when the third party transmits the first information from the third-party terminal to the control device. 
     For example, in the case where the object is a facility, by transmitting the authentication information from the portable terminal to the control device equipped in the facility, it is possible to make the control device perform a locking-unlocking control of locking or unlocking a door of the facility, an electric power source turning-on control of turning on an electric power source of an electric product in the facility, or the like. At this time, similarly to the second embodiment, by adding function restriction information for restricting the electric power source turning-on control to the authentication information that is transferred from the user terminal to the third-party terminal, it is possible to allow the third party to lock and unlock the door of the facility using the third-party terminal, but allow the third party not to utilize the electric product in the facility. Further, in the case where the authentication information that is transferred from the user terminal to the third-party terminal contains only authentication information for locking and unlocking the door of the facility in advance, by adding function permission information for permitting the electric power source turning-on control of turning on the electric power source of the electric product in the facility to the authentication information that is transferred from the user terminal to the third-party terminal, the third party is allowed to lock and unlock the door of the facility and utilize the electric product in the facility, using the third-party terminal.