Owner identity confirmation system, terminal and owner identity confirmation method

A terminal for an owner sameness confirmation system that includes a plurality of terminals and a plurality of authentication station servers, the terminal comprising:

• a storage unit configured to store identity confirmation information of an owner of the terminal, the identity confirmation information being stored in association with an electronic certificate in an authentication station server that issued the electronic certificate to the terminal;
• a confirmation request unit, including one or more processors, configured to transmit a confirmation request message including encrypted information obtained by encrypting the identity confirmation information stored in the storage unit using a public key for homomorphic encryption, and the public key to a partner terminal that is a target of owner sameness confirmation;
• a confirmation response unit, including one or more processors, configured to, upon receiving the confirmation request message, transmit a confirmation response message including response encrypted information, which is the result of calculating an encrypted text obtained by encrypting the identity confirmation information stored in the storage unit using the public key, and the encrypted information through computation corresponding to the homomorphic encryption, as a response to the transmission source of the confirmation request message;
• and
• a sameness determination unit, including one or more processors, configured to decrypt the response encrypted information, and determine whether or not the identity confirmation information of the owner of the terminal and identity confirmation information of an owner of the partner terminal match each other based on whether or not the decryption result matches a predetermined value.

An owner sameness confirmation method to be executed by a terminal of an owner sameness confirmation system that includes a plurality of terminals and a plurality of authentication station servers,

• wherein the terminal includes
• a storage unit configured to store identity confirmation information of an owner of the terminal,
• the method comprising:
• a step of transmitting a confirmation request message including encrypted information obtained by encrypting the identity confirmation information stored in the storage unit using a public key for homomorphic encryption, and the public key to a partner terminal that is a target of owner sameness confirmation;
• a step of, upon receiving the confirmation request message, transmitting a confirmation response message including response encrypted information, which is the result of calculating an encrypted text obtained by encrypting the identity confirmation information stored in the storage unit using the public key and the encrypted information through computation corresponding to the homomorphic encryption, as a response to the transmission source of the confirmation request message;
• and
• a step of decrypting the response encrypted information and determining whether or not the identity confirmation information of the owner of the terminal and identity confirmation information of an owner of the partner terminal match each other based on whether or not the decryption result matches a predetermined value.