| 摘要 |
PROBLEM TO BE SOLVED: To provide a product-sum arithmetic unit whose circuit scale is not enlarged by an extension degree (m) in operations on an extension field GF (2m). SOLUTION: This arithmetic unit 100 is a product-sum arithmetic unit which obtains 2n-bit vector D=(d0,..., d2n-1) by respectively calculating two vectors A=(a0,..., an-1) B=(b0,..., bn-1) which are expressed with (n) bits and a vector C=(c0,..., c2n-1) which is expressed with 2n bits, when (n) is defined as a natural number, according to equations dk=Σaibj+ck(mod2), (0<=k<=2n-2). i+j=k, 0<=i, j<=n-1 d2n-1=c2n-1...(1) At this time, the unit 100 is provided with logical product means 110 to 125, first exclusive logical sum means 130 to 138 and second exclusive logical sum means 140 to 146 for executing operations according to the equations.
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