| 摘要 |
PROBLEM TO BE SOLVED: To reduce the burden in designing and the cost of a device, to improve resource utilization efficiency and to enhance safety by improving a nonlinear transformation means S-Box of an encryption processing device by a common key encryption method. SOLUTION: The encryption processing device 11 is provided with a nonlinear transformation means 14 composed of a programmable logic device FPGA and capable of changing nonlinear arithmetic function such as matrix computation with a parameter. A key storage means 12 stores downloaded keys, and the constitution of the nonlinear transformation means 14 is changed by key data Sai, Sbi. Inputted data P is linearly transformed, in a linear transformation means 13, by rotary shift or the like in accordance with key data Ki, then is nonlinearly transformed, in the nonlinear transformation means 14, by matrix computation or the like in accordance with the internal structure set in accordance with the key data Sai, Sbi and outputted as data C. COPYRIGHT: (C)2004,JPO
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