METHOD AND DEVICE FOR HYPERELLIPTIC CURVE SCALAR MULTIPLE OPERATION

摘要

PROBLEM TO BE SOLVED: To provide a device for hyperelliptic curve scalar multiple operation used in a high-speed enciphering system.;SOLUTION: When calculating the scalar multiple of an element D of a Jacobian variety accompanying a hyperelliptic curve, two calculations each of which can be calculated independently are made into one set to reduce inverse element calculations included each one time in each calculation by using Montgomery Trick in prior calculations, and the multiplied by an integer k (k=2^s+h ((h) and (s) are integers)) which is to be internally calculated is calculated by calculating [k]D=[2^s-1]D+([2^s-1]D+[h]D) instead of calculating [k]D=[2^s]D+[h]D to replace doubling by addition. By making these two improvements, the number of times for multiplications and reverse element calculations on a definition body is reduced to constitute the device for hyperelliptic curve scalar multiple operation optimum for a genus two hyperelliptic curve.;COPYRIGHT: (C)2004,JPO&NCIPI