Owner identity confirmation system, certificate authority server and owner identity confirmation method

An authentication station server for an owner sameness confirmation system including a plurality of terminals and a plurality of authentication station servers, the authentication station server comprising:

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

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

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