Nippon Telegraph and Telephone Corporation

Mitsubishi Electric Corporation

Ntt Corporation

Toyohashi University of Technology

Junichi Tomida

Akira Nagai

Fumitaka Hoshino

Katsuyuki Takashima

Koutarou Suzuki

Atsushi Fujioka

Masanobu Kii

Koji Chida

Atsunori Ichikawa

A secure collation system performs secure-data-collation between first and second information processing apparatuses and includes the first and second information processing apparatuses. The second information-processing-apparatus creates, when receiving a first vector having a hash value of a key value of the first information-processing-apparatus as an element, a second vector by adding a dummy hash value to the first vector and rearranging the first vector by random permutation; creates a third vector having, as elements, a hash value of a key value of the second information-processing-apparatus and a hash value of a dummy key value; and transmits the second and third vectors to the first information-processing-apparatus. The first information-processing-apparatus calculates a hash value of an element of the third vector and creates a fourth vector having the hash value as an element; and collates matched values between each element of the third vector and each element of the fourth vector.

Secure consolidation system, information processing apparatus, secure consolidation method, and program

A key exchange system, for generating a shared key for performing encrypted communication between multiple communication devices, includes the multiple communication devices. Each of the multiple communication devices includes a memory, and a processor configured to generate a short term private key by using a private key, generate a short term public key on one of asymmetric pairing groups used for the ID based encryption, by using the short term private key, and generate a shared key for performing encrypted communication with another communication device by performing a first pairing operation using a private key generated on another one of the asymmetric pairing groups and a short term public key generated in the other communication device, and performing a second pairing operation using the short term private key of the communication device and public information used in generating a private key of the other communication device.

Key exchange system, method and program for generating a shared key for secure communication

A key exchange system in which a shared key is generated for executing encrypted communication between communication apparatuses according to an authenticated key exchange protocol using ID-based encryption, wherein each communication apparatus includes a memory and a processor configured to generate a short-term private key by using a private key of the communication apparatus; generate a short-term public key of the communication apparatus by using the short-term private key; generate private information on the communication apparatus by using the short-term private key, a short-term public key generated by another communication apparatus, and public information generated by the communication apparatus and said another communication apparatus or public information generated by a key delivering center; and generate the shared key for executing encrypted communication with said another communication apparatus by executing a pairing operation using the private key of the communication apparatus and the private information.

Key exchange system, communication apparatus, key exchange method and program

An encryption system for performing encryption and decryption by a multi-input inner product functional encryption having a function hiding property includes a setup unit configured to generate, taking a vector length m and the number of arguments &#x3bc; of an inner product function as input, a master secret key msk and a public parameter pp by using a setup algorithm of a single-input inner product functional encryption having a predetermined characteristic and having a function hiding property and a key generation algorithm of a common key encryption satisfying a predetermined condition, an encryption unit configured to generate, taking the master secret key msk, the public parameter pp, an index i of the arguments, and a vector x as input, a ciphertext ctcorresponding to the index i by using an encryption algorithm of the single-input inner product functional encryption and an encryption algorithm of the common key encryption.

Cipher system, encryption apparatus, decryption apparatus, cipher method, encryption method, decryption method and program

An inner-product functional encryption scheme in which the maximum length of a ciphertext and the maximum length of a secret key are not restricted can be constructed. An encryption device () generates a ciphertext ctin which a vector x is encrypted, using encryption setting information that is of a size depending on the size of the vector x and is generated using as input public information of a fixed size. A key generation device () generates a secret key skin which a vector y is set, using key setting information that is of a size depending on the size of the vector y and is generated using as input the public information. A decryption device () decrypts the ciphertext ctwith the secret key skto calculate an inner-product value of the vector x and the vector y.

Growing community of inventors

Tokyo, Japan

Junichi Tomida