Abstract:
A radio tag system including at least one radio tag that includes a plurality of data areas and a key storage area that stores key information corresponding to at least one data area; and a managing unit that manages access to the radio tag, and that includes a request receiving unit that receives from a user, a request to issue key information that allows access to one of the data areas, and an issuing unit that issues the key information in response to the request received.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a radio tag that can be accessed by a plurality of users, and information written in the radio tag by a user is prevented from being leaked to other users.  
         [0003]     2. Description of the Related Art  
         [0004]     In recent years, systems that use radio tags have been actively developed in various fields. For example, Japanese Patent Application Laid-Open No. 2000-285170 discloses a system that uses radio tags for managing life cycles of commodities.  
         [0005]     However, when a plurality of users use one radio tag, all the users can read out all pieces of information stored in the radio tag, and hence, there is a problem in that information is leaked among the users.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the present invention to at least solve the problems in the conventional technology.  
         [0007]     A radio tag according to one aspect of the present invention includes a plurality of data areas; and a key storage area that stores key information corresponding to at least one data area, wherein access to the one data area is allowed if key information corresponding to the one data area is provided.  
         [0008]     A radio tag system according to another aspect of the present invention includes at least one radio tag that includes a plurality of data areas; and a key storage area that stores key information corresponding to at least one data area; and a managing unit that manages access to the radio tag, and that includes a request receiving unit that receives a request to issue key information that allows access to at least one of the data areas in the radio tag; and an issuing unit that issues the key information in response to the request.  
         [0009]     According to still another aspect of the present invention, a method for managing access to at least one radio tag, the radio tag including a plurality of data areas, and a key storage area that stores key information corresponding to at least one data area includes receiving from a user, a request to issue a key that allows access to one of the data areas; and issuing a key in response to the request received.  
         [0010]     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a functional block diagram of a radio tag system according to an embodiment of the present invention;  
         [0012]      FIG. 2  is a functional block diagram of a radio tag managing apparatus according to the embodiment;  
         [0013]      FIG. 3  is a diagram of an example of a contract information DB;  
         [0014]      FIG. 4  is a diagram of data areas of a radio tag;  
         [0015]      FIG. 5  is a diagram of an example of a key information database;  
         [0016]      FIG. 6  is a flowchart of a process procedure of a contract process and a key issuance process performed by the radio tag managing apparatus;  
         [0017]      FIG. 7  is a flowchart of a process procedure of a key return process performed by the radio tag managing apparatus;  
         [0018]      FIG. 8  is a flowchart of a process procedure of an expiration process for a key, performed by the radio tag managing apparatus; and  
         [0019]      FIG. 9  is a functional block diagram of a computer that executes a radio tag managing program.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0020]     Exemplary embodiments of the present invention are explained in detail below with reference to the accompanying drawings.  
         [0021]      FIG. 1  is a functional block diagram of the radio tag system according to this embodiment. As shown in the figure, the radio tag system includes a plurality of radio tags  10 , a plurality of reader/writers  20 ,  30 , and  40 , a plurality of radio tag managing apparatuses  100  connected by a stationary network  60 , and a mobile network  70  connected to the stationary network  60  and the reader/writers  30 .  
         [0022]     An RFID service provider (RSP) providing a radio tag service (RFID service) uses the radio tag managing apparatus  100  to store information of the radio tags  10  in a radio tag database (DB) and manage the information. The radio tag managing apparatus  100  can control a large number of the reader/writers  20  through an RSP network  50 , and read and write the information of the radio tags  10  through the reader/writers  20 .  
         [0023]     The RSP supplies the radio tag  10  to a user, and gives the user an authority for using data areas of the radio tags  10  based on a contract with the user. The radio tag  10  has a plurality of data areas, and gives the user the authority for using data areas for each of the data areas. In other words, a plurality of users can use the radio tag  10 . Note that, if a user desires, the RSP can also give the user an authority for using the reader/writers  20 , the radio tag managing apparatus  100 , and the RSP network  50 . The RSP can also provide an Application Service Provider (ASP)  80  with the radio tag  10  or the like.  
         [0024]     The radio tag managing apparatus  100  can control the reader/writers  20  of other RSPs in cooperation with the radio tag managing apparatuses  100  of the other RSPs through the stationary network  60 . The radio tag managing apparatus  100  can also exchange data with the radio tags  10  of other RSPs.  
         [0025]     In a small-scale system, the reader/writers  20  may be arranged in one retail shop. In a large-scale system, the reader/writers  20  may be arranged in multinational corporations distributed all over the world. In the large-scale system, a plurality of radio tag managing apparatuses  100  may be arranged in a distributed manner.  
         [0026]     The reader/writers  30  and  40  are owned by individuals. The reader/writer  30  may be, for example, a reader/writer integrated in a cellular phone. The reader/writer  30  is connected to the radio tag managing apparatus  100  through the mobile network  70  and the stationary network  60 . The reader/writer  40  may be, for example, a reader/writer connected to a personal computer at home. The reader/writer  40  is connected to the radio tag managing apparatus  100  through the stationary network  60 . An individual can write information of the radio tag  10  of his/her own article, and write information in the radio tag  10  using these reader/writers.  
         [0027]     First, a user of the radio tag system according to this embodiment enters into a contract with the RSP, receives the radio tag  10  from the RSP, acquires a key for one of the many data areas of the radio tag  10 , and the user is permitted to use that data area. Note that the user can establish a radio tag system using a reader/writer and his/her own computer system. If necessary, the user can also establish a radio tag system using the reader/writer  20 , the radio tag managing apparatus  100 , the RSP network  50 , and the like.  
         [0028]     For example, a manufacturer of personal computers attaches the supplied radio tag  10  to a semi-finished product, or a product of a personal computer. The manufacturer uses the radio tag  10  for customization and production management in a manufacturing process as well as inventory management. When the manufacturer ships a commodity with the radio tag  10  attached to it, the manufacturer erases information of a data area in the radio tag  10 , and returns a key for the data area to the RSP, whereby the use ends according to the contract. The next user of the commodity can use the data area by entering into a radio tag use contract similar to the contract held by the previous user.  
         [0029]     Note that, for traceability of a commodity, information may be stored over the entire life cycle of the commodity. A part of the data areas of the radio tag  10  may be set such that anybody can read information out of that part, and even the manufacturer can not erase the information at the time of shipping the commodity.  
         [0030]     In the radio tag system according to this embodiment, a plurality of companies and individuals can share information about a commodity. For example, when a consumer informs a manufacturer of deficiency in a commodity, the consumer can write a state of the deficiency in the radio tag  10 , and can have a home delivery service deliver the radio tag  10  to a complaint-handling counter of a shop.  
         [0031]     The manufacturer secures one of the data areas in the radio tag  10  as an area for writing deficiency, and another data area as a common area that anybody can read. When a complaint is notified, the manufacturer discloses a key to the consumer such that the consumer can write deficiency in the area meant for writing deficiency. The consumer writes information about the deficiency in the radio tag  10  using the key. At the same time, the consumer writes information about delivery in the common area, and has a home delivery service deliver the radio tag  10  to the manufacturer. Being able to read information necessary for the delivery from the radio tag  10 , the home delivery service can deliver the radio tag  10 . However, the home delivery service cannot read the information about the deficiency.  
         [0032]     Thus, because the manufacturer shares the key with only the owner of the commodity, the manufacturer can acquire the information on the deficiency from the consumer without leaking the information to others. In the same way, a plurality of companies can share the data areas of the radio tag  10 .  
         [0033]      FIG. 2  is a functional block diagram of the constitution of the radio tag managing apparatus  100  according to this embodiment. As shown in the figure, the radio tag managing apparatus  100  includes a contract information DB  110 , a key information DB  120 , a contract managing unit  130 , a key managing unit  140 , a key term managing unit  150 , an external interface (I/F)  160 , and an overall control unit  170 . The contract information DB  110  and the key information DB  120  correspond to the radio tag DB shown in  FIG. 1 .  
         [0034]      FIG. 3  is a diagram of an example of the contract information DB  110 . As shown in the figure, the contract information DB  110  stores, for each user, a user ID for identifying the user, a user password for authenticating the user, a radio tag ID and an area number indicating the radio tag  10  and a data area that the user can use, contract conditions for using the radio tag  10  such as the number of times of writing in the data area, a key request mode indicating whether a lending period for a key is permanent or limited, information for settlement of accounts for use of the radio tag  10 , a contact address indicating a mailing address of the user.  
         [0035]     For example, a user with the user ID “userid-x” and the user password “pwd-x” uses a data area with the radio tag ID “uid-a” and the area number “0”. For the user, the contract condition is “contract-x”, the key request mode is “lease”, the information for settlement is “account-x”, and the contact address is “address-x”.  
         [0036]      FIG. 4  is a diagram of data areas of the radio tag  10 . As shown in the figure, the radio tag  10  has a system area, in which a UID and the like are written, and four data areas “area 0” to “area 3”. The radio tag  10  also includes areas “area 0 key ID” to “area 3 key ID”, in which area key IDs are stored, in association with the respective data areas. Only when a key ID designated in a read/write request coincide with the area key IDs stored, it is possible to perform read/write to the respective data areas. However, by setting an area key ID stored in the radio tag  10  to a specific value, it is also possible to perform read/write to a data area corresponding to the area key ID freely.  
         [0037]     The radio tag  10  includes, every four bytes, a LOCK bit and a Write Once Read Many (WORM) bit for controlling writing of data. When the LOCK bit is “0”, it is possible to write data in the radio tag  10 . However, when the LOCK bit is “1”, it is not possible to write data in the radio tag  10 . When the WORM bit is “0”, there is no limitation on the number of times of writing. However, when the WORM bit is “1”, once data is written in the radio tag  10 , the LOCK bit is rewritten to “1”, and the data cannot be overwritten.  
         [0038]      FIG. 5  is a diagram of an example of the key information DB  120  that stores information on a key rented out to a user. As shown in the figure, the key information DB  120  stores, for each data area of the radio tag  10 , a radio tag ID, an area number, and a key ID of a key rented out to a user. The key information DB  120  also stores a term of validity for a key rented out, and stores “returned” as a term of validity for a key not rented out.  
         [0039]     For example, for a key with the radio tag ID “uid-a” and the area number “0”, the key ID is “key 0” and the term of validity is Apr. 11, 2005. Note that it is assumed that a key ID registered in the key information DB  120  is written in the radio tag  10  as an area key ID.  
         [0040]     The contract managing unit  130  manages the radio tag  10 , and a data area for which the RSP enters into a contract for use with a user, using the contract information DB  110 . The contract managing unit  130  performs a process of providing a key to the user and return of the key from the user. Note that the contract managing unit  130  does not issue a key to, for example, a user who has not observed a contract in the past.  
         [0041]     The contract managing unit  130  manages the radio tag  10 , and a data area for which the RSP enters into a contract for use with a user, using the contract information DB  110 , whereby each data area of the radio tag  10  can be used by a different user.  
         [0042]     The key managing unit  140  manages a key rented out to a user using the key information DB  120 . The key managing unit  140  acquires a key from the key information DB  120  and issues the key to the user. The key managing unit  140  performs a process for registering a term of validity of the key in the key information DB  120 , and a return process for changing a term of validity in the key information DB  120  to “returned” for a returned key.  
         [0043]     The key term managing unit  150  manages a term of a key rented out to a user. Specifically, the key term managing unit  150  searches through the key information DB  120  periodically to find out a key with an expired term of validity. This makes it possible to urge a user to return the key.  
         [0044]     The external I/F  160  communicates with a user, the reader/writers  20 , and the like through the stationary network  60  and the RSP network  50 . For example, the external I/F  160  receives a request to issue a key from a user, and transmits an issued key to the user.  
         [0045]     The overall control unit  170  controls the entire radio tag managing apparatus  100 . Specifically, the overall control unit  170  performs shift of control among functional units, delivery of data among the functional units and storing units, and the like to thereby cause the radio tag managing apparatus  100  to function as one apparatus.  
         [0046]      FIG. 6  is a flowchart of the process procedure for contract process and key issuance process by the radio tag managing apparatus  100  according to this embodiment.  
         [0047]     As shown in the figure, in the radio tag managing apparatus  100 , the external I/F  160  receives contract and key issuance requests and parameters, and passes the contract and key issuance requests and the parameters to the overall control unit  170  (step S 101 ). The parameters include authentication information for a user, a radio tag ID and an area number of a data area for which a key is issued, a key request mode, a term of validity, contract conditions, information for settlement, and a contact address.  
         [0048]     The overall control unit  170  transfers the contract and key issuance requests to the contract managing unit  130  together with the parameters (step S 102 ). The contract managing unit  130  checks whether it is possible to enter into a contract, based on the parameters and a blacklist in which defaulters of contracts are registered. If it is possible to enter into a contract, the contract managing unit  130  registers contract information in the contract information DB  110 , based on the parameters (step S 103 ).  
         [0049]     The contract managing unit  130  responds to the overall control unit  170  with a key issuing ticket (step S 104 ). The overall control unit  170  shows the key issuing ticket to the key managing unit  140 , and requests a key (step S 105 ). The key issuing ticket includes a radio tag ID and an area number for requesting issuance of a key and a term of validity of the key.  
         [0050]     The key managing unit  140  issues the key and registers the term of validity in the key information DB  120  (step S 106 ). The key managing unit  140  passes the key to the overall control unit  170  (step S 107 ). Specifically, the key passed to the overall control unit  170  is a key ID. The overall control unit  170  passes the key to the external I/F  160  (step S 108 ). The external I/F  160  passes the key to the user (step S 109 ).  
         [0051]     Thus, the contract managing unit  130  registers contract information in the contract information DB  110 , and the key managing unit  140  issues a key for each data area and registers a term of validity of the key in the key information DB  120 . Consequently, it is possible to manage users and keys in association with the respective data areas of the radio tag  10 .  
         [0052]      FIG. 7  is a flowchart of the process procedure for the key return process performed by the radio tag managing apparatus  100  according to this embodiment.  
         [0053]     As shown in the figure, in the radio tag managing apparatus  100 , the external I/F  160  receives a key return request, and passes a key and related information included in the key return request to the overall control unit  170  (step S 201 ). The overall control unit  170  returns the key and the related information to the key managing unit  140  (step S 202 ). The related information includes information on contract conditions such as a radio tag ID, an area number, the number of times of writing in a data area, and the like.  
         [0054]     The key managing unit  140  performs the key return process for changing a term of validity in the key information DB  120  to “returned” (step S 203 ). The key managing unit  140  issues a key erasing ticket to the overall control unit  170  (step S 204 ). The key erasing ticket includes the related information.  
         [0055]     The overall control unit  170  sends the key erasing ticket to the contract managing unit  130  (step S 205 ). The contract managing unit  130  checks the contract information DB  110  (step S 206 ), and judges whether the returned key satisfies the contract conditions, such as the number of times of writing in a data area (step S 207 ).  
         [0056]     If the returned key does not satisfy the contract conditions, the contract managing unit  130  requests the overall control unit  170  to perform a contract-violation process for the user (step S 208 ). The overall control unit  170  performs the contract-violation process, and notifies the contract managing unit  130  of completion of the process for violation of contract (step S 209 ). As the contract-violation process, for example, the overall control unit  170  registers the user in a blacklist.  
         [0057]     The contract managing unit  130  performs contract completion process such as erasing of information corresponding to the key returned from the contract information DB  110  (step S 210 ). The contract managing unit  130  notifies the overall control unit  170  of completion of the contract (step S 211 ). The overall control unit  170  notifies the user of the completion of the contract through the external I/F  160  (step S 212 ).  
         [0058]     Thus, the key managing unit  140  changes the term of validity in the key information DB  120  to “returned” for the returned key, and the contract managing unit  130  erases the information corresponding to the key returned from the contract information DB  110 . Consequently, it is possible to open a data area, the contract of which is completed, to other users.  
         [0059]      FIG. 8  is a flowchart of the process procedure for expiration process for a key, performed by the radio tag managing apparatus  100 .  
         [0060]     As shown in the figure, in the radio tag managing apparatus  100 , when the key term managing unit  150  finds a key with an expired term of validity, the key term managing unit  150  notifies the overall control unit  170  of a key ID and expiration information of the key (step S 301 ). The overall control unit  170  notifies the external I/F  160  of a key collection request (step S 302 ). The external I/F  160  notifies the user of the key collection request (step S 303 ).  
         [0061]     If the key is returned immediately (“Yes” at step S 304 ), the overall control unit  170  performs the key return process shown in  FIG. 7  (step S 309 ). On the other hand, if the key is not returned immediately (“No” at step S 304 ), the overall control unit  170  instructs the contract managing unit  130  to register the user in a blacklist (step S 305 ), and urges the user to return the key (step S 306 ). When the external I/F  160  receives the key returned from the user (step S 307 ), the overall control unit  170  instructs the contract managing unit  130  to delete the user from the blacklist (step S 308 ), and performs the key return process shown in  FIG. 7  (step S 309 ).  
         [0062]     In this way, the key term managing unit  150  notifies the overall control unit  170  of the key with an expired term of validity, and the overall control unit  170  notifies the user of a key return request through the external I/F  160 . Consequently, it is possible to prevent the key with an expired term of validity from being left unreturned.  
         [0063]     As described above, in this embodiment, the radio tag  10  includes plural data areas, and the areas for storing keys corresponding to the respective data areas. The contract managing unit  130  manages a user for each of the data areas using the contract information DB  110 , the key managing unit  140  issues a key to the user, for using the data area, using the key information DB  120 , and the user uses a radio tag ID using the key. Thus, the user is capable of accessing only that data area for which the key is acquired. Even when a plurality of users use the radio tag  10 , it is possible to prevent information written in the radio tag  10  by a user, from being used by the other users.  
         [0064]     Note that, in this embodiment, the radio tag managing apparatus is explained. However, it is possible to obtain a radio tag managing program having the same functions as the radio tag managing apparatus by realizing the constitution held by the radio tag managing apparatus with software. Thus, a computer that executes this radio tag managing program is explained next.  
         [0065]      FIG. 9  is a functional block diagram of a constitution of the computer that executes the radio tag managing program according to this embodiment. As shown in the figure, a computer  200  includes a RAM  210 , a CPU (central processing unit)  220 , an HDD  230 , a LAN (local area network) interface  240 , an input/output interface  250 , and a DVD drive  260 .  
         [0066]     The RAM  210  stores programs, intermediate results during execution of the programs, and the like. The CPU  220  reads out the program from the RAM  210  and executes the program.  
         [0067]     The HDD  230  is a disk device that stores programs and data. The LAN interface  240  connects the computer  200  to other computers through a LAN.  
         [0068]     The input/output interface  250  connects an input device such as a mouse or a keyboard and a display device. The DVD drive  260  reads data from and writes data into a DVD.  
         [0069]     A radio tag managing program  211  executed in the computer  200  is stored in a DVD, read out from the DVD by the DVD drive  260 , and installed in the computer  200 .  
         [0070]     Alternatively, the radio tag managing program  211  is stored in databases of other computer systems connected through the LAN interface  240 , read out from these databases, and installed in the computer  200 .  
         [0071]     The radio tag managing program  211  installed is stored in the HDD  230 , read out to the RAM  210 , and executed by the CPU  220  as a radio tag managing process  221 .  
         [0072]     In the explanation of this embodiment, a user designates a radio tag and a data area to request issuance of a key. However, the present invention is not limited thereto. The present invention can be applied in the same manner, when a user designates a necessary size of an area to request use of a radio tag, and the radio tag managing apparatus provides the user with the radio tag and a data area together with a key.  
         [0073]     According to one aspect of the present invention, even if a plurality of users use a radio tag, it is possible to prevent information written in the radio tag by a user from being leaked to other users.  
         [0074]     Moreover, it is possible to use the data areas effectively.  
         [0075]     Furthermore, it is possible to take measures not to issue a key to a violator of the contract.  
         [0076]     Furthermore, it is possible to make it less likely that a key issued is left unreturned.  
         [0077]     Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.