| 摘要 |
For calculating a product of a first and a second integer, each given by even digits, a multiplier comprises a first unit for calculating a first residue congruent to the product modulo a prime number by the use of one-to-one correspondence of each integer to an exponent of a primitive root of the prime number, a second unit for calculating a second residue congruent to the product modulo an even number equal to the prime number less one, and a third unit for processing the first and the second residues to a processed result. A higher and a lower half of digits of the product are given by the processed result and the second residue. Each integer may be given on the basis of a predetermined radix, such as 10 or 2, by h digits with the prime number given by an h-th power of the radix plus one. Preferably, the second residue is calculated by multiplying a higher and a lower half of the digits of the first integer by a higher and a lower half of the second integer and by combining the product in a predetermined manner.
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