Abstract: Provided is an authentication system capable of preventing determination that authentication of a person to be authenticated succeeds even though determination as to whether matching information matches registration information is not performed when authentication using two factors is performed. A determination unit 43 determines whether or not the matching information matches the registration information. A signature generation unit 21 of a client 10 generates a signature based on the message by using a signature key. A signature determination unit 34 determines whether or not the signature is a correct signature by using a first verification key, a message, and the signature. When it is determined that the matching information matches the registration information and it is determined that the signature is the correct signature, the authentication determination unit 37 determines that the authentication succeeds.

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: 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: biometric A generation apparatus includes converts a received key to an encoded key by using an encoding function of an error correcting code, and generates a sketch by applying a first composite transformation on received fuzzy data and the encoded key. A reconstruction apparatus receives a first sketch and a second sketch, generates a composite sketch by applying second composite transformation on the first and second sketches, and reconstruction calculates difference between the two keys used to generate the first and second sketches based on the composite sketch.

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 matching system in which leakage of the registration information from the client can be prevented, even when the concealed information generated from registration information is stored in the client, is provided. The concealed information storage unit 15 of the client 1 stores concealed information generated by concealing registration information with a public key. The concealed evaluation value calculation unit 17 of the client 1 calculates a concealed evaluation value of an evaluation value indicating similarity between the registration information and matching information input for matching with the registration information, based on the matching information and the concealed information. The determination unit 25 of the server 2 determines whether the matching information and the registration information match or not, based on the evaluation value obtained by cancelling concealment of the concealed evaluation value received from the evaluation value transmission unit 18.

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: Provided is an authentication system capable of preventing determination that authentication of a person to be authenticated succeeds even though determination as to whether matching information matches registration information is not performed when authentication using two factors is performed. A determination unit 43 determines whether or not the matching information matches the registration information. A signature generation unit 21 of a client 10 generates a signature based on the message by using a signature key. A signature determination unit 34 determines whether or not the signature is a correct signature by using a first verification key, a message, and the signature. When it is determined that the matching information matches the registration information and it is determined that the signature is the correct signature, the authentication determination unit 37 determines that the authentication succeeds.

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.

Abstract: An objective of the present invention is to enable user authentication with an intensity that is in accordance with a current situation. In the present invention, a situation management device retains a current situation of an overall system including a relevant system being connected and an operator. A registration device: accepts registration information; and stores the registration information and/or information associated with the registration information as storage information in a storage device. An authentication device: accepts authentication information; and outputs the authentication information and/or information associated with the authentication information as comparison information.