Abstract: A conventional biometric authentication system has been time-consuming and labor-intensive for users since the users are requested to re-register their biometric information. According to an aspect of the present disclosure, a biometric authentication system includes an update value generation unit configured to generate an update value, a first update processing unit configured to update, using the update value, a template generated based on biometric information, and a second update processing unit configured to update, using the update value, a verification key generated along with the template based on the biometric information using the update value.

Abstract: In a recovery verification system, a template storage unit stores a template acquired by encrypting registration input information being biometric information about a registrant by using a secret key. A random number generation unit generates a random number in response to a request from the client. A protected template generation unit conceals the template by the random number, and transmits a protected template to the client. A determination unit acquires, from the client, information about a concealment index that is acquired by concealing a degree of similarity between registration input information and collation information being biometric information about an authenticated subject and is calculated based on the collation information and the protected template. A determination unit generates an index acquired by decrypting the concealment index by using a public key associated with the secret key and the random number, and performs authentication, based on the index.

Abstract: An encryption system comprises a key generation apparatus that generates an encryption key relating to the authority to generate a ciphertext from a plaintext, a homomorphic operation key relating to the authority to execute a homomorphic operation on a ciphertext that remains encrypted and whose authority is weaker than that of the encryption key, and a decryption key relating to the authority to decrypt ciphertext; an encryption apparatus that generates a ciphertext from a plaintext using the encryption key; a homomorphic operation apparatus that executes a homomorphic operation on the ciphertext using the homomorphic operation key; and a decryption apparatus that decrypts ciphertext using the decryption key.

Abstract: A comparison system includes a key generation means for generating a common key being common to each of a plurality of pieces of registration information, and also generating a plurality of unique keys being unique for each of the plurality of pieces of registration information by using a plurality of pieces of identification information, a concealment means (126) for generating a plurality of pieces of concealment information. The client includes a concealment index calculation means for calculating a plurality of concealment indexes representing a similarity degree between comparison information and each of the plurality of pieces of concealment information. The verification server includes a determination means for generating a plurality of indexes acquired by decrypting each of the plurality of concealment indexes, and also performing authentication of the comparison information, based on whether any of the plurality of indexes indicates a value within a predetermined range.

Abstract: A collation system 10 includes divide registered information to first information and second information, and to provide the second information to a server apparatus 200, perform a first step for similarity calculation between the registered information and collation information inputted for collation with the registered information, based on the collation information and the first information, send a calculation result of the first step to the server apparatus 200, perform a second step for the similarity calculation based on the calculation result of the first step received from a client terminal 100, and the second information, send a calculation result of the second step to the client terminal 100, and perform a third step for the similarity calculation based on the calculation result of the second step received from the server apparatus 200, and the first information to calculate similarity between the registered information and the collation information.

Abstract: In order to provide an information matching system achieving an information matching scheme that takes a lower cost and uses secure biometric information, the information matching system includes a concealment apparatus, a decryption apparatus, and a similarity calculating apparatus. The concealment apparatus transmits, to the similarity calculating apparatus, concealed information including information concealing obtained matching information by linear conversion using random numbers. The similarity calculating apparatus calculates, from obtained one or more pieces of registration information and the concealed information received from the concealment apparatus, a concealed similarity which is a value concealing a similarity between the matching information and the registration information, and to transmit the calculated concealed similarity to the decryption apparatus.

Abstract: A storing information generation apparatus obtains registration information and an identifier capable of identifying the registration information, to generate a first individual key from the common key and the identifier, and to generate storing information obtained by linearly converting the registration information using the common key and the first individual key. A matching information concealment apparatus obtains matching information to generate concealed matching information concealing the matching information using an encryption key. A concealed similarity calculation apparatus calculates a concealed similarity from the storing information and the concealed matching information. A decryption apparatus generates a second individual key from the common key and the identifier, and calculates a similarity between the registration information and the matching information from the concealed similarity, a decryption key corresponding to the encryption key, the common key, and the second individual key.

Abstract: The client includes a random number generation unit which generates a random number, a concealed information storage unit which stores concealed information generated by concealing registered information and the generated random number using a secret key, and a response computation unit which, on the basis of a challenge transmitted from the server, the collation information input for collation with the registered information, and the concealed information, computes a response corresponding to the challenge and including a concealed index, generated by concealing an index indicating closeness between the registered information and the collation information. The server includes a challenge generation unit which generates the challenge using a public key corresponding to the secret key, and a determination unit which uses the public key and the random number transmitted from the client to determine whether or not the response transmitted from the client corresponds to the challenge.

Abstract: An encryption system comprises a key generation apparatus that generates an encryption key relating to the authority to generate a ciphertext from a plaintext, a homomorphic operation key relating to the authority to execute a homomorphic operation on a ciphertext that remains encrypted and whose authority is weaker than that of the encryption key, and a decryption key relating to the authority to decrypt ciphertext; an encryption apparatus that generates a ciphertext from a plaintext using the encryption key; a homomorphic operation apparatus that executes a homomorphic operation on the ciphertext using the homomorphic operation key; and a decryption apparatus that decrypts ciphertext using the decryption key.

Abstract: A collation system 20, which is provided with a client 30 and a server 40, the client 30 includes: a random number generation unit 31 which generates a random number; a concealed information storage unit 32 which stores concealed information generated by concealing registered information and the generated random number using a concealment key; and a concealed index computation unit 33 which, on the basis of the collation information input for collation with the registered information and the concealed information, computes a concealed index, generated by concealing an index indicating closeness between the registered information and the collation information; the server 40 includes a determination unit 41 which uses a release key corresponding to the concealment key and the random number transmitted from the client 30 to determine whether or not the index can be acquired from the concealed index transmitted from the client 30.

Abstract: A client 30 includes a concealed information storage unit 31 which stores concealed information obtained by concealing registered information by use of a public key, an information generation unit 32 which, on the basis of the concealed information and a random number, generates, by use of the public key, generation source information that is information for generating a challenge, and a response computation unit 33 which, by use of the challenge sent from a server 40, collation information to be collated against the registered information, and a random number, computes a response corresponding to the challenge. The server 40 includes a key storage unit 41 which stores a secret key corresponding to the public key, and a challenge generation unit 42 which generates the challenge on the basis of the generation source information sent from the client 30.