| 摘要 |
PROBLEM TO BE SOLVED: To enable the execution of a cipher algorithm to execute the processing of a 4 byte base for a 32-bit microcomputer by executing the processing including the operation regulated by a function by using an additive operation or additive instruction and executing a circular shift by forming a code of a 2n-bit length using a circular shift instruction. SOLUTION: The key data K2, K3 of an n-bit length are segmented from a message andπ3 (A, B) is subjected to the first additive operation of A and the key data K2 with the data A of the n-bit length. Further, the circular shift at the first bit number and the second additive operation with the key data K3 are carried out and the circular shift at the second bit number is carried out. The set of the data of the n-bit length subjected to the third additive operation with this data and B is determined as the function to be outputted. The key data K2, K3 are used for the initial value and the processing including the operation regulated by the functionπ3 is executed by using the additive instruction for the additive operation and the circular shift instruction for the circular shift, by which the code of the 2n-bit length is formed.
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