| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To realize a high-security encryption processing device and an encryption processing method with improved difficulty in analysis. <P>SOLUTION: The encryption processing device is so constituted that: in the Feistel type common key block encryption processing wherein an SPN type F function having a non-linear transformation section and a linear transformation section is repeatedly performed a plurality of rounds, the linear transformation processing of the F function corresponding to each of the plurality of rounds is performed as a linear transformation processing to which a square MDS (Maximum Distance Separable) matrix is applied; and arbitrary m column vectors contained in the inverse matrix of the square MDS matrix to be set at least in each of the consecutive even number round and consecutive odd number round constitute a square MDS matrix. In this constitution, the encryption processing having improved resistance to a linear attack in the common key block encryption can be achieved. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
