Title: Encryption device, encryption method, and computer program
Application Number: 200580001259 Application Date: 2005.08.30
Publication Number: 1879138 Publication Date: 2006.12.13
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: G09C1/00
Applicant(s) Name: Sony Corp. Address:
Inventor(s) Name: Shirai Taizo
Attorney & Agent: qian weimin
Abstract:
     There are provided a highly safe encryption device and an encryption method increasing the difficulty of decryption. A Feistel type common key block encryption repeatedly executes the SPN type F function having a non-linear conversion unit and a linear conversion unit by a plurality of rounds. The linear conversion of the F function corresponding to each of the rounds is made a linear conversion employing a square MDS (Maximum Distance Separable) matrix. Arbitrary m column vectors contained in the inverse matrix of the square MDS matrix set in each of at least in continuous even-number rounds and continuous odd-number rounds is set as a square MDS matrix. By the present configuration, it is possible to realize encryption having improved resistance against linear attack in the common key block encryption.
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