Patent application number | Description | Published |
20140136094 | PROXIMITY DETERMINATION METHOD, PROXIMITY DETERMINATION DEVICE, AND PROXIMITY DETERMINATION SYSTEM - A proximity determination method includes: collecting a first concealed vector based on a linear combination of a row vector of a key matrix, first numerical information, and a first random number, the key matrix being generated by adding a random number vector as a last column to a matrix in which a threshold for determining a proximity range is a diagonal element; collecting a second concealed vector based on the linear combination, second numerical information, and a second random number; calculating a remainder vector, the remainder vector being a remainder obtained from a difference between the collected first concealed vector and the second concealed vector when the key matrix is used as a modulus; and determining whether the first numerical information and the second numerical information belong to the proximity range, based on the calculated remainder vector. | 05-15-2014 |
20140185794 | ENCRYPTION PROCESSING APPARATUS AND METHOD - A device that uses homomorphic encryption is disclosed. The device obtains a first encrypted polynomial, a second encrypted polynomial, a first encrypted weight, and a second encrypted weight by respectively encrypting a first polynomial, a second polynomial, a first weight, and a second weight by using a homomorphic encryption scheme, and obtains an encrypted secure distance corresponding to encryption of a secure distance. | 07-03-2014 |
20140185797 | CRYPTOGRAPHY PROCESSING DEVICE AND CRYPTOGRAPHY PROCESSING METHOD - A device that uses homomorphic encryption is disclosed. The device includes a public key data generator configured to generate public key data, and a secret key data generator configured to generate secret key data that includes, as a secret key, an integer that is an element of a matrix obtained as a product of the first public key matrix element and an inverse matrix of the secret key matrix and that is not a multiple of the plain text space size. | 07-03-2014 |
20140233726 | DECRYPTION METHOD, RECORDING MEDIUM STORING DECRYPTION PROGRAM, DECRYPTION DEVICE, KEY GENERATION METHOD, AND RECORDING MEDIUM STORING KEY GENERATION PROGRAM - A decryption method includes receiving an input of an n-dimensional vector whose elements other than a first element are all zero, or of the first element. The vector is a ciphertext obtained by encrypting a plaintext being an integer not less than 0 and less than s with a public key, or by performing an operation on a plurality of ciphertexts without decrypting them. The public key is associated with an n×n invertible matrix V defined as a secret key of homomorphic cryptography by using n integers, and is a matrix B being an Hermite normal form of V. The decryption method also includes: acquiring an element w which is coprime to s and which is one of elements of a matrix W=dV | 08-21-2014 |
20150046708 | INFORMATION PROCESSING TECHNIQUE FOR SECURE PATTERN MATCHING - An encrypted first polynomial that is obtained by encrypting, in a homomorphic encryption method that handles a polynomial processing, a first polynomial, is received from another computer. The first polynomial is represented by using, as coefficients, components of a first binary vector generated from first data in first order that is either ascending order or descending order with respect to degree of the first polynomial. Then, a predetermined processing in an encrypted text space is performed by using the encrypted first polynomial and an encrypted second polynomial that is obtained by encrypting a second polynomial in the homomorphic encryption method. The second polynomial is represented by using, as coefficients, components of a second binary vector generated from second data in second order that is different from the first order with respect to degree of the second polynomial. Then, a result of the predetermined processing is sent back. | 02-12-2015 |
20150207630 | INFORMATION PROCESSING APPARATUS, AND INFORMATION PROCESSING METHOD - A non-transitory computer-readable recording medium stores an information processing program that causes a computer to execute a process including, generating feature information based on organism information of a user; calculating a first cryptogram based on a logical operation of the feature information generated and a random number; and encrypting the first cryptogram into a second cryptogram by using a cryptographic algorithm capable of calculating a Hamming distance in an encrypted state. | 07-23-2015 |
20150270964 | ENCRYPTION DEVICE, ENCRYPTION METHOD, INFORMATION PROCESSING DEVICE, AND ENCRYPTION SYSTEM - An encryption server receives encrypted data which is encrypted by using a public key of a first user and which is added with auxiliary information calculated using a combination of a secret key and the public key of the first user and data to be encrypted. Then, the encryption server generates re-encrypted data obtained by re-encrypting the encrypted data using the auxiliary information added to the encrypted data, a public key of a second user, and encrypted information related to the secret key of the first user which is encrypted with the public key of the second user. | 09-24-2015 |
20150280914 | CIPHERTEXT PROCESSING DEVICE, CIPHERTEXT PROCESSING METHOD, COMPUTER-READABLE RECORDING MEDIUM, AND INFORMATION PROCESSING DEVICE - A ciphertext processing device acquires a first polynomial into which first text data is converted with a first order and which is encrypted with a first public key and a first square-value polynomial into which square-value vector data of each component of the first text data is converted with the first order and which is encrypted with the first public key. The ciphertext processing device acquires a second polynomial into which second text data is converted with a second order and which is encrypted with the first public key and a second square-value polynomial into which square-value vector data of each component of the second text data is converted with the second order and which is encrypted with the first public key. The ciphertext processing device determines whether the second text data is included in the first text data, using the each polynomial. | 10-01-2015 |