Cooperation service providing system and server apparatus

1. A cooperation service providing system comprising:

a re-encryption key issuing apparatus;

a plurality of service apparatuses for providing various services to a user by using an identification (ID) issued for the user; and

a cooperation apparatus communicably connected to the plurality of service apparatuses and the re-encryption key issuing apparatus, wherein the cooperation apparatus comprises:

a first memory configured to store public keys of the re-encryption key issuing apparatus and the service apparatuses,

a second memory configured to store a re-encryption key for implementing re-encryption processing of enabling ciphertext data transmitted by a first service apparatus to be decrypted using a private key of a second service apparatus,

first generation circuitry configured to generate, upon receiving the ciphertext data transmitted by the first service apparatus, re-encrypted data by performing re-encryption processing for the ciphertext data using the stored re-encryption key,

first transmission circuitry configured to transmit the generated re-encrypted data to the second service apparatus, and

second transmission circuitry configured to transmit the stored public keys to the service apparatuses, and

the first service apparatus of the plurality of service apparatuses comprises:

a third memory configured to store the issued ID in association with user information unique to the service apparatus,

a fourth memory configured to store a private key of the service apparatus,

third transmission circuitry configured to transmit, to the cooperation apparatus, ciphertext data in which the ID of the user encrypted using a public key of the re-encryption key issuing apparatus stored in the first memory, and a request to acquire user information specified by the ID and stored in the second service apparatus, in response to an operation of the user,

acquisition circuitry configured to acquire, upon receiving the re-encrypted data transmitted by the cooperation apparatus, the encrypted ID by decrypting the re-encrypted data using the stored private key,

readout circuitry configured to read out the user information corresponding to the acquired ID from the third memory, and

fourth transmission circuitry configured to transmit the readout user information to the second service apparatus via the cooperation apparatus.

2. A cooperation service providing system comprising:

a re-encryption key issuing apparatus:

a plurality of service apparatuses for providing various services to a user by using an identification (ID) issued for the user; and

a cooperation apparatus communicably connected to the plurality of service apparatuses, and the re-encryption key issuing apparatus, wherein

the cooperation apparatus comprises:

a first memory configured to store public keys of the re-encryption key issuing apparatus and the service apparatuses,

a second memory configured to store a re-encryption key for implementing re-encryption processing of enabling ciphertext data transmitted by a first service apparatus to be decrypted using a private key of a second service apparatus,

first generation circuitry configured to generate, upon receiving the ciphertext data transmitted by the first service apparatus, re-encrypted data by performing re-encryption processing for the ciphertext data using the stored re-encryption key,

first transmission circuitry configured to transmit the generated re-encrypted data to the second service apparatus, and

second transmission circuitry configured to transmit the stored public keys to the service apparatuses, and

the first service apparatus of the plurality of service apparatuses comprises:

a third memory configured to store the issued ID linked with a first code unique to the service apparatus in association with user information unique to the service apparatus,

a fourth memory configured to store a private key of the service apparatus,

third transmission circuitry configured to transmit, to the cooperation apparatus, ciphertext data in which the ID of the user generated by using a public key of the re-encryption key issuing apparatus stored in the first memory and the first code linked with the ID are encrypted, and a request to acquire user information specified by the ID and stored in the second service apparatus, in response to an operation of the user,

acquisition circuitry configured to acquire, upon receiving the re-encrypted data transmitted by the cooperation apparatus, the encrypted ID by decrypting the re-encrypted data using the stored private key,

encryption circuitry configured to encrypt the decrypted ID to generate a second code,

readout circuitry configured to read out the user information corresponding to the first code from the third memory,

specifying circuitry configured to specify the user information by comparing the first code with the second code, and

fourth transmission circuitry configured to transmit the readout user information to the second service apparatus via the cooperation apparatus.

3. A server apparatus of a cooperation service providing system, the cooperation service providing system including: a re-encryption key issuing apparatus, a plurality of service apparatuses for providing various services to a user by using an identification (ID) issued for the user, and a cooperation apparatus communicably connected to the plurality of service apparatuses a first service apparatus of the plurality of service apparatuses includes: a first memory which stores the issued ID in association with user information unique to the service apparatus, a second memory which stores a private key of the service apparatus, first generation circuitry which generates, in response to an operation of the user, ciphertext data by encrypting using a public key of the re-encryption key issuing apparatus received from the cooperation apparatus for the ID of the user, first transmission circuitry which transmits, to the cooperation apparatus, the generated ciphertext data and a request to acquire user information specified by the ID and stored in a second service apparatus, acquisition circuitry which acquires, upon receiving re-encrypted data transmitted by the cooperation apparatus, the encrypted ID by decrypting the re-encrypted data using the stored private key, readout circuitry which reads out the user information corresponding to the acquired ID from the first memory, and second transmission circuitry which transmits the readout user information to the second service apparatus via the cooperation apparatus, the server apparatus comprising:

a third memory configured to store public keys of the re-encryption key issuing apparatus and the service apparatuses;

a fourth memory configured to store a re-encryption key for implementing re-encryption processing of enabling ciphertext data transmitted by the first service apparatus to be decrypted using a private key of the second service apparatus;

second generation circuitry configured to generate, upon receiving the ciphertext data transmitted by the first service apparatus, re-encrypted data by performing re-encryption processing for the ciphertext data using the stored re-encryption key;

third transmission circuitry configured to transmit the generated re-encrypted data to the second service apparatus; and

fourth transmission circuitry configured to transmit a stored public key of the stored public keys to the service apparatuses.

4. A cooperation service providing system comprising:

a re-encryption key issuing apparatus;

a plurality of service apparatuses for providing various services to a user; and

a cooperation apparatus communicably connected to the plurality of service apparatuses and the re-encryption key issuing apparatus,

wherein the cooperation apparatus comprises:

a first memory configured to store public keys of the re-encryption key issuing apparatus and the service apparatuses,

a second memory configured to store a re-encryption key for implementing re-encryption processing of enabling ciphertext data transmitted by a first service apparatus to be decrypted using a private key of a second service apparatus,

first generation circuitry configured to generate, upon receiving the ciphertext data transmitted by the first service apparatus, re-encrypted data by performing re-encryption processing for the ciphertext data using the stored re-encryption key,

first transmission circuitry configured to transmit the generated re-encrypted data to the other second service apparatus, and

second transmission circuitry configured to transmit stored public keys to the service apparatuses, and

the first service apparatus of the plurality of service apparatuses comprises:

a third memory configured to store cooperation information or between the service apparatuses in association with the user,

a fourth memory configured to store a private key of the service apparatus,

second generation circuitry configured to generate, in response to an operation of the user, ciphertext data by encrypting the cooperation information associated with the user by using a public key of the re-encryption key issuing apparatus transmitted by the cooperation apparatus,

third transmission circuitry configured to transmit the generated ciphertext data to the cooperation apparatus, and

acquisition circuitry configured to acquire, upon receiving the re-encrypted data transmitted by the cooperation apparatus, the encrypted cooperation information by decrypting the re-encrypted data using the private key.

5. A server apparatus of a cooperation service providing system, the cooperation service providing system including: a re-encryption key issuing apparatus, a plurality of service apparatuses for providing various services to a user, and a cooperation apparatus communicably connected to the plurality of service apparatuses, a first service apparatus of the plurality of service apparatuses includes: a first memory which stores cooperation information between the service apparatuses in association with the user, a second memory which stores a private key of the service apparatus, first generation circuitry which generates, in response to an operation of the user, ciphertext data by encrypting the cooperation information associated with the user by using a public key of the re-encryption key issuing apparatus transmitted by the cooperation apparatus, first transmission circuitry which transmits the generated ciphertext data to the cooperation apparatus, and acquisition circuitry which acquires, upon receiving re-encrypted data transmitted by the cooperation apparatus, the encrypted cooperation information by decrypting the re-encrypted data using the private key, the server apparatus comprising:

a third memory configured to store public keys of the re-encryption key issuing apparatus and the service apparatuses;

a fourth memory configured to store a re-encryption key for implementing re-encryption processing of enabling ciphertext data transmitted by the first service apparatus to be decrypted using a private key of a second service apparatus;

second generation circuitry configured to generate, upon receiving the ciphertext data transmitted by the first service apparatus, re-encrypted data by performing re-encryption processing for the ciphertext data using the stored re-encryption key;

third transmission circuitry configured to transmit the generated re-encrypted data to the second service apparatus; and

fourth transmission circuitry configured to transmit the stored public keys to the service apparatuses.