Patent application number | Description | Published |
20080253561 | Common-Key Block Encryption Device Common-Key Block Encryption Method, and Common-Key Block Encryption Program - Disclosed is a common-key block encryption device including first Feistel-type hash means that divides a plain text into a PA block and a PB block and adds the PB block, which is compressed by a hash function, and the PA block to generate a unit block intermediate text; unit block encryption means that encrypts the unit block intermediate text to generate a unit block intermediate cipher text; pseudorandom number generation means that generates an intermediate random number based on the unit block intermediate cipher text; addition means that adds the intermediate random number and the PB block and outputs an addition result; second Feistel-type hash means that outputs a result that is a combination of a second addition result, generated based on the addition result compressed by a hash function and the unit block intermediate cipher text, and the addition result; and cipher text output means that outputs the output result as a cipher text. | 10-16-2008 |
20090138710 | Message Authentication Device, Message Authentication Method, Message Authentication Program and Storage Medium therefor - A message authentication device, a message authentication method, a message authentication program and a storage medium therefor are provided, so as to realize higher speed processing than an authentication mode of existing block cipher, in combination of block cipher and one of its parts, with theoretical security in accordance with a high efficient preliminary process and with an efficient amount of available memory. The message authentication device includes: input means for inputting a message: padding means for padding the message, setting its length always to a constant of a block length, and outputting the message as a padded message; modified tree hash means for outputting hash values of one block by repeating a process of arranging hash functions with small input/output widths, corresponding to the padded message, generated based on parts of block cipher; adjustment value added encryption means for encrypting the hash values so as to set a tag; and output means for coupling and outputting the tag and the message. | 05-28-2009 |
20090196416 | TWEAKABLE BLOCK ENCRYPTION APPARATUS, METHOD, AND PROGRAM - A tweakable block cipher apparatus includes an input unit that receives a pair of a plaintext M and a tweak; an offset calculation unit that calculates a sum of a value (E(K, const)), which is generated by encrypting a constant plaintext (constant const) using a block cipher, and the tweak and outputs a value (G(Ksub, E(K, const)+tweak), which is generated by encrypting the result (E(K, const)+tweak) using a partial block cipher (G), as an offset; an internal encryption unit that calculates a sum of the offset and the plaintext M, encrypts the sum using the block cipher E, calculates a sum (E(K, M+offset)+offset) of the result (E(K, M+offset)) and the offset, and outputs the sum as a ciphertext (C); and an output unit that outputs the ciphertext. | 08-06-2009 |
20100329449 | ADJUSTMENT-VALUE-ATTACHED BLOCK CIPHER APPARATUS, CIPHER GENERATION METHOD AND RECORDING MEDIUM - There is provided an adjustment-value-attached block cipher apparatus realizing block cipher processing that the amount of processing is small in adjustment-value-attached block cipher. The adjustment-value-attached block cipher apparatus includes: an encryption section performing encryption by a block cipher system; an input section accepting plaintext, an adjustment value and instruction information indicating first or second cipher processing; and a generator dividing the adjustment value into first and second adjustment values, encrypting the first adjustment value using the encryption section to generate cipher for offset, determining an offset value according to the cipher for offset and the second adjustment value, determining the sum of the offset value and the plaintext, and encrypting the sum using the encryption section to generate first ciphertext when the instruction information indicates the first cipher processing, and encrypting the plaintext using the encryption section to generate second ciphertext when the instruction information indicates the second cipher processing. | 12-30-2010 |
20110150225 | ENCRYPTION DEVICES FOR BLOCK HAVING DOUBLE BLOCK LENGTH, DECRYPTION DEVICES, ENCRYPTION METHOD, DECRYPTION METHOD, AND PROGRAMS THEREOF - An encryption device for a block having double block length permutates a plaintext of 2 n bits based on a universal hash function so as to generate first and second intermediate variables of n bits each, encrypts the first intermediate variable with a tweak that is a result in which the second intermediate variable is shortened to m bits using an encryption function for m-bit tweak n-bit block cipher so as to generate a third intermediate variable of n bits, encrypts the second intermediate variable with a tweak that is a result in which the third intermediate variable is shortened to m bits using the encryption function so as to generate a fourth intermediate variable of n bits, concatenates the third and fourth intermediate variables and inversely mingles the concatenated result based on a universal hash function so as to generate a ciphertext of 2 n bits. | 06-23-2011 |
20110211691 | COMMON KEY BLOCK ENCRYPTION DEVICE, COMMON KEY BLOCK ENCRYPTION METHOD, AND PROGRAM - A common key block encryption device includes a first hash unit applying locked key permutation to a variable-length s-bit plaintext, and outputting a fixed-length n-bit first block and a second (s-n)-bit block; a first encryption processing unit outputting a third block encrypted by element of n-bit block tweakable block cipher using tweak, inputting the first block; a second encryption processing unit generating a random number (s-n)-bit block with a result of group computation of the third block and the first block as input by using an arbitrary cipher having theoretical security at least against a known-plaintext attack; and a second hash unit applying the locked key permutation to the result of the group computation of the random number block and the second block, and to the third block to output a fifth n-bit block and a sixth (s-n)-bit block. The fifth and sixth blocks are concatenated into an s-bit encryption. | 09-01-2011 |
20120057702 | TAG GENERATION APPARATUS, TAG VERIFICATION APPARATUS, COMMUNICATION SYSTEM, TAG GENERATION METHOD, TAG VERIFICATION METHOD, AND RECORDING MEDIUM - The tag generation apparatus of the present invention includes a hash unit (12) that applies a hash function to a message to generate a hash value, a random number encryption unit (14) that applies an encryption function having a first key to a random number that is independent of the message to generate a first intermediate variable, a masked encryption unit (15) that applies the encryption function having a second key to the sum of the random number and the hash value to generate a second intermediate variable, and a tag generation unit (16) that generates as the tag a value contained in bits of a predetermined number of bits that is less than or equal to the number of bits of the random number and that are extracted from the exclusive OR of the first intermediate variable and the second intermediate variable. | 03-08-2012 |
20120269342 | BLOCK ENCRYPTION DEVICE AND METHOD AND COMPUTER PROGRAM - In block cipher based on generalized Feistel network, pseudorandomness and strong-pseudorandomness may be fulfilled efficiently. In encrypting a plaintext of kn-bit blocks, Feistel permutation is applied in terms of 2n bits as a unit, and then block-based permutation based on a binary de Bruijn graph with symmetrical type 2 branch coloring is applied. The Feistel permutation and the block-based permutation are grouped together to form a round. The round is repeatedly performed a preset number of times to output a ciphertext. | 10-25-2012 |
20120314857 | BLOCK ENCRYPTION DEVICE, BLOCK DECRYPTION DEVICE, BLOCK ENCRYPTION METHOD, BLOCK DECRYPTION METHOD AND PROGRAM - A block encryption device receives b-bit tweak T and generates, by keyed hash function employing key K | 12-13-2012 |
20130308775 | BLOCK ENCRYPTION DEVICE, DECRYPTION DEVICE, ENCRYPTING METHOD, DECRYPTING METHOD AND PROGRAM - A block encrypting device of the present invention includes: a mixing means ( | 11-21-2013 |
20140137211 | APPARATUS-SPECIFIC INFORMATION GENERATION DEVICE, APPARATUS-SPECIFIC INFORMATION GENERATION METHOD, TERMINAL APPARATUS, AND AUTHENTICATION SYSTEM - The present invention has: a dynamic random access memory (DRAM); a refresh controller that receives information related to a range of the number of lost bits that are lost by stopping refresh processing of the DRAM, and controls a time to stop the refresh processing to achieve the range of the number of lost bits; and a physical information mapping unit that generates device specific information based on position information of the lost bits generated by stopping the refresh processing. It is preferable that the refresh controller corrects the time to stop the refresh processing based on the number of current lost bits to achieve the range of the number of lost bits set. | 05-15-2014 |
20150180666 | UNIVERSAL HASH FUNCTION COMPUTING DEVICE, METHOD AND PROGRAM - A universal hash function calculation device includes a message register sequentially outputs a message of which the bit number is a prime number and of which the length is such that the smallest primitive root when the bit number is set as the modulo is 2, outputting said message one bit at a time. A cyclic key register cyclically permutates a key having the same number of bits as the message, and sequentially outputs a cyclic key vector obtained as a result of the cyclical permutation. On the basis of the sequentially-output cyclic key vector and a message bit that is sequentially output one bit at a time, a logical product calculation unit outputs the cyclic key vector when the message bit is 1, and outputs an all-zero vector having the same bit number as the cyclic key vector when the message bit is 0. A cumulative sum calculation unit accumulates calculation results having the same number as the output bit number and calculates the exclusive disjunction. | 06-25-2015 |
Patent application number | Description | Published |
20150248347 | CONTENT PROVIDING APPARATUS AND METHOD, AND COMPUTER PROGRAM PRODUCT - According to an embodiment, a content providing apparatus includes: a receiving unit that receives a request for content from a communication terminal; an obtaining unit that obtains the content according to the request; a rendering unit that renders the content and generates rendering information; a storage that stores therein the rendering information of the content; a judging unit that judges, according to the content, whether a storage area, which stores therein the rendering information, of the storage is overwritable; a allocating unit that allocates the storage area as an overwritable or non-overwritable storage area, according to the judgment result; a determining unit that determines whether to change the content, and determines a change method used when the content is changed; a content changing unit that changes the content, using the rendering information, according to the change method; and a transmitting unit that transmits the changed content to the communication terminal. | 09-03-2015 |
20150249722 | CONTENT PROVIDING APPARATUS AND METHOD, AND COMPUTER PROGRAM PRODUCT - According to an embodiment, a content providing apparatus includes a receiving unit, an analyzing unit, a determining unit, a changing unit, and a transmitting unit. The receiving unit receives a request for content from a communication terminal. The analyzing unit analyzes the content requested by the communication terminal. The determining unit determines a method for changing the content, based on a result of the analysis by the analyzing unit and communication terminal information indicating performance or state of the communication terminal. The changing unit changes the content by the change method determined by the determining unit. The transmitting unit transmits the content changed by the changing unit to the communication terminal. | 09-03-2015 |
Patent application number | Description | Published |
20080205316 | COMMUNICATION APPARATUS, COMMUNICATION METHOD AND COMMUNICATION SYSTEM - A communication apparatus includes an image information acquisition unit configured to acquire new image information to be transmitted to a display terminal through a wireless access point, a storage unit configured to temporarily store the image information, a decision unit configured to decide to change a state of a wireless communication processing unit of the display terminal from a power save state to a normal state when an amount of the image information stored in the storage unit is not less than a predetermined threshold value, a message generation unit configured to generate a change instruction message in response to decision of the decision unit, and a transmission unit configured to transmit the change instruction message to the display terminal through the wireless access point to instruct the display terminal to change the state of the wireless communication processing unit from the power save state to the normal state. | 08-28-2008 |
20090147014 | Apparatus, method, and recording medium for detecting update of image information - When a processor, which transits from a first mode that causes a guest operating system to operate to a second mode that causes a virtual machine monitor managing the guest operating system to operate, when previously set transition condition is satisfied, transits to the second mode, a determining unit determines a cause or the transition. When it is determined that an execution of a process related to a completion of writing the image information in an image storage unit on the guest operating system is the cause, a detecting unit detects an updated portion representing an unmatched portion of the image information between before and after writing. | 06-11-2009 |
20090204957 | VIRTUAL COMPUTER SERVER APPARATUS, AND UPDATE IMAGE DETECTION METHOD - A virtual computer server apparatus includes an image information memory to store image information upon dividing into pages, the page being a memory of a predetermined size, an update unit configured to update the image information stored in the image information memory in accordance with operation of the application program, an update page detection unit configured to detect an update page from the pages storing image information transmitted to the terminal and displayed by the terminal as a display area, an update image detection unit configured to detect the image information updated by the update unit from image information in the update page before updated and image information in the update page after updated. | 08-13-2009 |
20100218184 | Information processing device, method, and computer program product - A setting storage unit stores first setting information that defines an operation of a first application that runs on a guest OS and second setting information that defines an operation of a second application that runs on at least one of another guest OS and a host OS. A correspondence storage unit stores first identification information for identifying the first setting information and second identification information for identifying the second setting information, in association with each other. An alternative access gaining unit reads from the correspondence storage unit the second identification information corresponding to the first identification information of the first setting information for which an access request is received, and accesses the second setting information of the second identification information that is read out, in place of the first setting information for which the access request is received. | 08-26-2010 |
20120250756 | COMMUNICATION APPARATUS AND CONTROL METHOD FOR COMMUNICATION APPARATUS - A signaling unit of a display terminal establishes communication with a content server, video communication terminal, and PC server through a communication unit, and transmits/receives image data compressed by MPEG2, MPEG4, and JPEG. A media control unit switches compression schemes for decoding in a media processing unit on the basis of the received image data. The media processing unit performs decoding processing including inverse orthogonal transformation processing and dequantization processing in accordance with the switched compression scheme. At this time, a single processing circuit performs inverse orthogonal transformation processing and dequantization processing. | 10-04-2012 |
20130002521 | SCREEN RELAY DEVICE, SCREEN RELAY SYSTEM, AND COMPUTER -READABLE STORAGE MEDIUM - According to one embodiment, a screen relay device includes a communication unit that receives first image information from relay source devices, and transmits second image information to a relay destination device, a determining unit that determines a storage area of the first image information in a first storage unit, a rendering unit that renders the first image information in the determined storage area, and a screen transfer unit. The screen transfer unit compares the first image information corresponding to an updated region where the image information stored in the first storage unit has been updated by the rendering of the rendering unit and the second image information corresponding to the updated region to extract a difference region, and writes the first image information of the difference region to a second storage unit as the second image information. | 01-03-2013 |