| 摘要 |
<P>PROBLEM TO BE SOLVED: To perform a modular multiplication operation of quadruple bit length using a modular multiplier having a bit length limit. <P>SOLUTION: A modular multiplication operation unit comprising: a bit data division processing unit, in which a multiplicand A, a multiplier B and a modulus N as input values are respectively expanded to division input values with bit lengths of a given bit length or less; a n/2 bit dedicated modular multiplier which calculates temporary modular multiplication values consisting of temporary quotient data and temporary remainder data, by performing recursive modular multiplication based on a predetermined operation algorithm using an arithmetic unit having a bit length limit on the division input values; a modular multiplication temporary bit data conversion unit which calculates quotient data Q and remainder data R (A*B(modN)=Q*2<SP POS="POST">n</SP>+R) as operation results of the modular multiplication for the input values, by performing a predetermined addition/subtraction operation after extracting the predetermined temporary quotient data and temporary remainder data from the calculated temporary modular multiplication values. <P>COPYRIGHT: (C)2012,JPO&INPIT |
