| 摘要 |
PROBLEM TO BE SOLVED: To perform a first S-P conversion or non-linear conversion S-linear conversion P in the substitution processing of non-linear conversion S-linear conversion P-non-linear conversion S in a common key block cryptograph with less frequencies of table reference and operation in accordance with package environment. SOLUTION: This device refers to tables S1, S2, S3, and S4 by inputs x1, x2,..., x8; takes the exclusive ORs of the outputs S1(x1), S2(x2), S3(x2), S4(x4) to obtain U1; takes the exclusive ORs of S2(x5), S3(x6), S4(x7), S1(x8) to obtain U2; obtains U1(+)U2→U3; rotates U2 upward by 1 byte; and obtains an exclusive OR of the result and U3 to output the result U4 and U3. |
