| 摘要 |
A device for calculating a modular multiplication comprises a unit for analyzing (100) positions of the multiplier by using a look-ahead algorithm in order to obtain a multiplication shifting value (sm). In addition, a unit for determining (104) an intermediate result shifting value is provided that determines a positive intermediate result shifting value. A unit (106) then calculates a multiplicand shifting value (sc) as a difference between the intermediate result shifting value (sz) and the multiplication shifting value (sm). The intermediate result from the previous iteration step and from the multiplicand are then shifted (108) by the corresponding shifting quantities (sc and sz) in order to then carry out a three-operand addition (112) with the shifted values optionally while taking look-ahead parameters (vn and vc) into consideration. The shifting of the intermediate result and of the multiplicand with regard to a fixed module enables the more efficient use of shifters since the multiplication shifting value (sm), which has a tendency to be large, does not dictate the shifter dimensioning.
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