DISCRETE LOGARITHM CALCULATING METHOD AND APPARATUS WHICH USES A PRECOMPUTING TABLE CONSISTING OF MULTIPLICATION OF PRIME FACTORS

摘要

PURPOSE: A discrete logarithm calculating method and apparatus are provided to reduce calculation time of a discrete logarithm question by establishing and using a pre-computing table.;CONSTITUTION: An initial value generating unit(310) creates initial values having different index. A function calculation unit(320) calculates a function value by applying a repetition function to each initial value. A distinguished point grasp unit(330) calculates a new function value by applying the repetition function through the function calculation unit in case the function value does not conform to a fixed distinguished point. The distinguished point grasp unit stores the function value and an index in a pre-computing table in case the function value conforms to the fixed distinguished point.;COPYRIGHT KIPO 2012