scispace - formally typeset
Search or ask a question
Author

Fumihiko Sano

Other affiliations: Panasonic
Bio: Fumihiko Sano is an academic researcher from Toshiba. The author has contributed to research in topics: Encryption & Key generation. The author has an hindex of 4, co-authored 6 publications receiving 114 citations. Previous affiliations of Fumihiko Sano include Panasonic.

Papers
More filters
Patent
11 Jul 2001
TL;DR: Expanded key schedule circuit for common key encryption system in which expanded keys are used in a predetermined order in data randomizing process for encryption and in a reversed order for decryption, comprises round processing circuits connected in series as discussed by the authors.
Abstract: Expanded key schedule circuit for common key encryption system in which expanded keys are used in a predetermined order in data randomizing process for encryption and in a reversed order in data randomizing process for decryption, comprises round processing circuits connected in series. The round processing circuits subject the common key or sub key of a previous stage to a round function to output a sub key. The sub key of the last stage is equal to the common key. The expanded keys are generated from the sub keys.

42 citations

Patent
18 Aug 2000
TL;DR: In this paper, an extended key generator, encryption/decryption unit, and storage medium are disclosed, in which as each of key transform functions, a transform process is done by an S box (substitution table) on the basis of a first key obtained from the inputted key, and an adder computes a corresponding one of extended keys based on a value obtained by shifting the transformed result of the S box to the left.
Abstract: There are disclosed an extended key generator, encryption/decryption unit, and storage medium, in which as each of key transform functions, a transform process is done by an S box (substitution table) on the basis of a first key obtained from the inputted key, and an adder computes a corresponding one of extended keys on the basis of a value obtained by shifting the transformed result of the S box to the left, and a second key obtained from the inputted key.

32 citations

Patent
24 Nov 1999
TL;DR: In this article, the transmission data includes sender's key recovery data obtained by encrypting recovery information for recovering a key for decrypting the encrypted data body to allow a key recovery agent registered by a sender to decrypt the recovery information.
Abstract: In an encryption apparatus for encrypting a data body to contain an encrypted data body in transmission data and transmitting the transmission data to a receiver, the transmission data includes sender's key recovery data obtained by encrypting recovery information for recovering a key for decrypting the encrypted data body to allow a key recovery agent registered by a sender to decrypt the recovery information, and receiver's key recovery data obtained by encrypting the recovery information for recovering the key for decrypting the encrypted data body to allow a key recovery agent registered by a receiver to decrypt the recovery information.

30 citations

Patent
11 Oct 1996
TL;DR: In this paper, a ciphering device capable of increasing safety while compatibility with DES (data encryption standard) is maintained is provided, which is provided with two identically structured key schedule parts A, B for developing two ciphering keys, which are obtainable by bisecting key information consisting of prescribed bit lines.
Abstract: PROBLEM TO BE SOLVED: To provide a ciphering device capable of increasing safety while compatibility with DES(data encryption standard) is maintained. SOLUTION: This device is provided with two identically structured key schedule parts A, B for developing two ciphering keys, which are obtainable by bisecting key information consisting of prescribed bit lines, each into an intermediary key for stirring an inputted message; with an exclusive OR part 14 for determining an exclusive OR against the two intermediary keys outputted from these two key schedule parts A, B; and with a stirring part for stirring the inputted message, using one of the intermediary keys if the two keys are detected being identical to each other with the exclusive OR turning zero, and using both keys if the two keys compared are detected being unidentical to each other. COPYRIGHT: (C)1998,JPO

4 citations

Patent
12 Jul 2000
TL;DR: In this paper, the extended key is used in reverse order at the time of ciphering and deciphering, respectively, two round functions f1 and fn+1 are set to be inverse functions to each other having the same number of stages from the first stage as that from the last stage.
Abstract: PROBLEM TO BE SOLVED: To provide a ciphering device capable of avoiding the occurrence of a delay time for generating an extended key, and also generating On-the-fly key. SOLUTION: In an extended key generating part 3 of a ciphering device using a common key block ciphering system in which the extended key is used in reverse order at the time of ciphering and deciphering, respectively, two round functions f1 and fn+1 are set to be inverse functions to each other having the same number of stages from the first stage as that from the last stage, respectively. Thus, it is possible to sequentially generate the extended key immediately and also in order of use by using the extended key as an input at the time of both ciphering and deciphering. Moreover, the extended key generation at the time of ciphering is fundamentally the same as that at the time of deciphering.

4 citations


Cited by
More filters
Patent
31 Aug 2011
TL;DR: In this article, a method for modifying an image is presented, which consists of displaying an image, the image comprising a portion of an object; determining if an edge of the object is in a location within the portion; and detecting movement in a member direction, of an operating member with respect to the edge.
Abstract: A method is provided for modifying an image. The method comprises displaying an image, the image comprising a portion of an object; and determining if an edge of the object is in a location within the portion. The method further comprises detecting movement, in a member direction, of an operating member with respect to the edge. The method still further comprises moving, if the edge is not in the location, the object in an object direction corresponding to the detected movement; and modifying, if the edge is in the location, the image in response to the detected movement, the modified image comprising the edge in the location.

434 citations

Patent
21 May 2004
TL;DR: In this paper, a data storage and retrieval device and method is described, which includes at least one magnetic storage medium configured to store target data and at least a re-configurable logic device comprising an FPGA coupled to the at least 1 magnetic medium and configured to read a continuous stream of target data therefrom, having been configured with a template or as desired to fit the type of search and data being searched.
Abstract: A data storage and retrieval device and method is disclosed. The device includes at least one magnetic storage medium configured to store target data and at least one re-configurable logic device comprising an FPGA coupled to the at least one magnetic storage medium and configured to read a continuous stream of target data therefrom, having been configured with a template or as otherwise desired to fit the type of search and data being searched. The re-configurable logic device is configured to receive at least one search inquiry in the form of a data key and to determine a match between the data key and the target data as it is being read from the at least one magnetic storage medium. This device and method can perform a variety of searches on the target data including without limitation exact and approximate match searches, sequence match searches, image match searches and data reduction searches. This device and method may be provided as part of a stand-alone computer system, embodied in a network attached storage device, or can otherwise be provided as part of a computer LAN or WAN. In addition to performing search and data reduction operations, this device may also be used to perform a variety of other processing operations including encryption, decryption, compression, decompression, and combinations thereof.

255 citations

Patent
29 Aug 2008
TL;DR: An integrated circuit for data encryption/decryption and secure key management is described in this paper, which is used in conjunction with other integrated circuits, processors, and software to construct a wide variety of secure data processing, storage, and communication systems.
Abstract: An integrated circuit for data encryption/decryption and secure key management is disclosed. The integrated circuit may be used in conjunction with other integrated circuits, processors, and software to construct a wide variety of secure data processing, storage, and communication systems. A preferred embodiment of the integrated circuit includes a symmetric block cipher that may be scaled to strike a favorable balance among processing throughput and power consumption. The modular architecture also supports multiple encryption modes and key management functions such as one-way cryptographic hash and random number generator functions that leverage the scalable symmetric block cipher. The integrated circuit may also include a key management processor that can be programmed to support a wide variety of asymmetric key cryptography functions for secure key exchange with remote key storage devices and enterprise key management servers. Internal data and key buffers enable the device to re-key encrypted data without exposing data. The key management functions allow the device to function as a cryptographic domain bridge in a federated security architecture.

128 citations

Patent
22 Mar 2007
TL;DR: An encryption technique for encrypting a plurality of data blocks of a data segment where the encryption selectively switches between a blockwise independent randomized encryption mode and a cipher block chaining (CBC) encryption mode based on a configurable feedback stride was disclosed in this article.
Abstract: An encryption technique is disclosed for encrypting a plurality of data blocks of a data segment where the encryption selectively switches between a blockwise independent randomized (BIR) encryption mode and a cipher block chaining (CBC) encryption mode based on a configurable feedback stride. A corresponding decryption technique is also disclosed.

124 citations

Patent
14 Dec 2006
TL;DR: In this paper, a symmetric master key is derived from the private key of the asymmetric key pair in a key device, and the symmetric key is stored in a computer memory location.
Abstract: One aspect relates to a process and associated device that provides a private key of an asymmetric key pair in a key device. A symmetric master key is derived from the private key of the asymmetric key pair. The symmetric master key is stored in a computer memory location. The symmetric master key is used to encrypt or decrypt a file encryption key. The file encryption key can encrypt or decrypt files. In another aspect, the user can still access the files even if a user deactivates the key device by encrypting or decrypting the file encryption key directly from the symmetric master key.

118 citations