摘要 |
<p>A system and method configured for applying Montgomery style reduction directly to negative quantities as well as positive values, producing the new form which does not require conditional operations to move values into the positive range. The low-order components of the resulting product, or partially completed product, can be reduced either by the addition of multiples of the modulus, as is usual in the standard Montgomery multiplication which accepts positive values, or by subtracting multiples of the modulus, which of course depends on the actual computation. Signed versions of the Montgomery values in a Montgomery computation are used to avoid the conditional addition and subtraction that can leak information, for example, using a two's complement representation.</p> |