发明名称 |
DATA TRANSFORMATION DEVICE AND RECORDING MEDIUM HAVING RECORDED THEREON A PROGRAM FOR IMPLEMENTING THE SAME |
摘要 |
A plurality of round processing parts (38) are provided each of which contains a nonlinear function part (304), and each nonlinear function part (304) comprises: a first key-dependent linear transformation part (341) which performs a linear transformation based on a subkey; a splitting part (342) which splits the output from the first key-dependent linear transformation part into n pieces of subdata; a first nonlinear transformati on part (343) which nonlinearly transforms those pieces of subdata, respectively; a second key-dependent linear transformation part (344) which linearly transforms those nonlinearly transformed outputs based on a subkey and outputs n pieces of transformed subdata; a second nonlinear transformation part (345) which nonlinearly transforms those transformed subdata; and a combining part (346) which combines the nonlinearly transformed outputs. An n x n matrix, which represents the linear transformation in the second key-dependent linear transformation part (344), is formed by n vectors whose Hamming weights are equal to or larger than T-1 for a security threshold T, thereby increasing the invulnerability again st differential cryptanalysis and linear cryptanalysis. |
申请公布号 |
CA2421142(C) |
申请公布日期 |
2004.05.11 |
申请号 |
CA19992421142 |
申请日期 |
1999.01.27 |
申请人 |
NIPPON TELEGRAPH AND TELEPHONE CORPORATION |
发明人 |
MATSUMOTO, TSUTOMU;OHTA, KAZUO;KANDA, MASAYUKI;TAKASHIMA, YOUICHI;AOKI, KAZUMARO;UEDA, HIROKI |
分类号 |
H04L9/14;(IPC1-7):H04L9/14 |
主分类号 |
H04L9/14 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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