Fujitsu Corporation

Kouhei Shigeta

Hiroshi Tsuda

Avradip Mandal

Arnab Roy

Hart Montgomery

Takeshi Shimoyama

Yoshinori Yaginuma

Ryota Kamakari

Toshiyuki Ishiguro

A method of equality verification using relational encryption including receiving a relational key that includes a first relational key component and a registration ciphertext that includes an encryption of a first plaintext data set. The method includes storing the registration ciphertext without decrypting the registration ciphertext. After the storing of the registration ciphertext, the method includes receiving an authentication request and communicating a safeguard data set that includes a random challenge in response to the authentication request. The method includes receiving an encrypted response that is generated based on the safeguard data set and a second plaintext data set. The method includes verifying a relationship between the encrypted response and the registration ciphertext using the relational key without decrypting the encrypted response and without decrypting the registration ciphertext. The relationship indicates that equality exists between the first and the second plaintext data sets.

Relational encryption for password verification

A method includes receiving biometric data, the biometric data non-uniformly distributed and processing the biometric data to a level of randomness as a plaintext vector, the level of randomness associated with a security level. The method also includes encrypting the plaintext vector using a relational linearity encryption scheme to generate a linearity ciphertext representative of the plaintext vector, encrypting the plaintext vector using a relational proximity encryption scheme to generate a proximity ciphertext representative of the plaintext vector, and communicating the linearity ciphertext and the proximity ciphertext to an authentication server. The method further includes receiving from the authentication server an authentication signal for the security level indicative of a linearity relationship between the linearity ciphertext and a registration linearity ciphertext discovered using a relational linearity key and of a proximity relationship between the proximity ciphertext and a registration proximity ciphertext detected using a relational proximity key.

Relational encryption

Growing community of inventors

Yokohama, Japan

Kouhei Shigeta