Encrypted text verification system, method, and recording medium

An encrypted text verification system, comprising:

• an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using a signature key;
• a registration data generation circuitry configured to generate registration data based on the encrypted data and a verification key;
• a storage device configured to store the registration data as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data;
• a first data verifying request generation circuitry configured to generate a first data verifying request in which input data to be verified has been encrypted by using a random number;
• a first data verifying determination circuitry configured to verify the registration template stored in the storage circuitry and the first data verifying request to produce a determined result;
• a first verified result generation circuitry configured to generate, as a first verified result, a combination of a message that has been randomly selected and a part or all of the registration template corresponding to the determined result;
• a decryption circuitry configured to decrypt the first verified result to produce a decrypted result;
• a second data verifying request generation circuitry configured to generate a second data verifying request based on the decrypted result and the message included in the first verified result;
• a second data verifying determination circuitry configured to generate a second data verifying determination based on the second data verifying request and the registration data of the registration template recorded in the storage circuitry;
• and
• a second verified result generation circuitry configured to generate, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination.

An encrypted text verification system, comprising:

• an encryption circuitry configured to calculate encrypted data by encrypting input data to be concealed by using a secret key;
• a registration data generation circuitry configured to generate registration data based on the encrypted data and a public key;
• a storage device configured to store the registration data as a registration template in a storage circuitry together with an identifier for uniquely identifying the registration data;
• a first data verifying request generation circuitry configured to generate a first data verifying request in which input data to be verified has been encrypted by using a random number;
• a first data verifying determination circuitry configured to verify the registration template stored in the storage circuitry and the first data verifying request to produce a determined result;
• a first verified result generation circuitry configured to generate, as a first verified result, a combination of a message that has been randomly selected and a part or all of the registration template corresponding to the determined result;
• a decryption circuitry configured to decrypt the first verified result to produce a decrypted result;
• a second data verifying request generation circuitry configured to generate a second data verifying request based on the decrypted result and the message included in the first verified result;
• a second data verifying determination circuitry configured to generate a second data verifying determination based on the second data verifying request and the registration data of the registration template recorded in the storage circuitry;
• and
• a second verified result generation circuitry configured to generate, as a second verified result, an identifier of the registration data corresponding to the second data verifying determination.