Modulo N multiplication of two binary numbers and application to exponentiation for public key encryption

摘要

The computation procedure produces a number of sub-products using a recursive relationship. The modulo number is subtracted from each sub-product, leaving the sub-product unchanged if the result of the subtraction is negative or modifying the value of the sub-product if the result is positive. The result is added to the product of the first multiplier and a co-efficient from the second multiplier. The result has subtracted from it the number resulting from the previous subtraction and test, and again the result is retained if the subtraction proves negative, or modified if not.