Patent application number | Description | Published |
20080205646 | COMPUTER-READABLE RECORDING MEDIUM STORING DATA DECRYPTION PROGRAM, DATA DECRYPTION METHOD, AND DATA DECRYPTION DEVICE - A method, device and computer-readable recording medium that stores therein a computer program for data decryption to execute processing when encrypted communication data including encrypted data obtained by encrypting plain text data and communication attributive data representing information of a data size of communicated data is received, the computer program making a computer execute notifying for receiving only the communication attributive data in the encrypted communication data and notifying the data size represented by the received communication attributive data to a preparing unit which prepares a storage area for storing the encrypted communication data in temporary storage incorporated in the computer. The computer program also enables the computer to execute storing the encrypted communication data in the prepared storage area and decrypting the encrypted data contained in the encrypted communication data, which is stored in the storage area, to obtain the plain text data. | 08-28-2008 |
20080219435 | Information transmitting apparatus, information transmitting method, and computer product - An information transmitting apparatus encrypts and transmits transmit data that includes contents for which transmission instruction has been received, an authentication code, and padding. The information transmitting apparatus includes a padding calculating unit that calculates a size of the padding based on an encrypting algorithm, a size of the authentication code and a size of the contents; a transmit-data size calculating unit that calculates a size of the transmit data from the size of the padding, the size of the authentication code, and the size of the contents; a generating unit that generates, using the size of the transmit data, a header that indicates a type of the transmit data and the size of the transmit data; an encrypting unit that encrypts the transmit data; and a transmitting unit that transmits the header and the encrypted transmit data. | 09-11-2008 |
20100031016 | PROGRAM METHOD, AND DEVICE FOR ENCRYPTION COMMUNICATION - An encryption communication method for performing communication that includes a data transfer phase for transmission of content data and a handshake phase for user authentication or agreement on the transmission method for content data, the method comprising: storing one set of a plurality of content data for multiple users in a common transmission communication region provided for the multiple users; transferring the stored one set of the plurality of content data during the data transfer phase when transferring content data of the multiple users to a communication target device; and receiving the stored one set of the plurality of content data using a plurality of transmission-reception communication regions provided for each of the multi users is provided. | 02-04-2010 |
20100183144 | Cipher processing apparatus - A cipher processing apparatus for arithmetic operations of an FO function and an FL function comprising: an FL function operating unit for generating a 2N-bit output based on a first extension key; a partial function operating unit for generating an N-bit output based on second and third extension keys; an N-bit intermediate register for storing an output of the partial operating unit; a 2N-bit first data register for storing data based on the output of the FL function operating unit; and a controller for making the partial function operating unit perform six cycles, inputting an output of the intermediate register to the FL function operating unit, and storing the data based on the output of the FL function operating unit in the first data register, in a first case in which the FL function uses a result of an arithmetic operation of the FO function. | 07-22-2010 |
20100278332 | DATA CONVERSION FUNCTION PROCESSOR | 11-04-2010 |
20100278340 | ENCRYPTION DEVICE, ENCRYPTION METHOD AND STORAGE MEDIUM STORING ITS PROGRAM - When processing a data conversion function of a MISTY structure, such as the FO function of MISTY1, the logical calculation result t | 11-04-2010 |
20110075837 | CRYPTOGRAPHIC APPARATUS AND METHOD - This cryptographic apparatus executes calculations according to an FI function including a first non-linear function S | 03-31-2011 |
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 |
20140169555 | INFORMATION PROCESSING APPARATUS, TAMPERING DETECTION APPARATUS, INFORMATION PROCESSING METHOD, TAMPERING DETECTION METHOD, AND COMPUTER PRODUCT - An information processing apparatus includes a processor configured to identify a data length that is longer than a data length of plain text data and that is a multiple of a predetermined block length; calculate a data length difference of the data length of the plain text and the data length; generate a first code that indicates the calculated data length difference; generate a second code that is calculated from the plain text data and is of a data length that is within a remaining data length acquired by subtracting a data length of the generated first code from the data length difference; create padding that includes the generated second code, has the first code at an end, and is of a length equivalent to the data length difference; concatenate the created padding to an end of the plain text data to generate concatenated data; and output the concatenated data. | 06-19-2014 |
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 |
20150074384 | SECURE BOOT METHOD, SEMICONDUCTOR DEVICE AND RECORDING MEDIUM - A secure boot method for a system, the system including a processor and a storage medium configured to store a program, a plurality of first partial hash values calculated based on a plurality of first partial programs into which the program is divided, and a first legitimate hash value which is a hash value calculated based on a plurality of first legitimate partial hash values, the plurality of first legitimate partial hash values being calculated based on a plurality of legitimate partial programs. The secure boot method includes calculating, a second calculated hash value based on the plurality of first partial hash values, and determining, whether or not the second calculated hash value matches the first legitimate hash value to continue the start-up processing of the system when the determination indicates match, and suspend the start-up processing of the system when the determination does not indicate match. | 03-12-2015 |