Device and Method of modular multiplication for modular exponentiation on Javacard

摘要

PURPOSE: A modular multiplier for exponentiation in a java card and a multiplying method thereof are provided to perform a high-speed operation process for the exponentiation by forming a modular multiplication module according to Montgomery algorithm. CONSTITUTION: A modular multiplier for exponentiation in a java card includes a basic operation module for performing basic calculation such as addition, subtraction, multiplication, and division. The basic operation module is used for performing a high-speed calculation process for operational terms A and B of n-bits on a Java card(100). The basic operation module includes a common buffer and a carry buffer. The common buffer has 2n+2 bits to recycle a memory. The carry buffer is used for storing a carry.