An Efficient Implementation of RSA Digital Signature Algorithm

RSA is the most widely used digital signature algorithm in E-Commerce and the complexity of large integer operation is the main factor that affects the efficiency of a RSA system. In this paper, a n carry array based large integer denotation approach is proposed to speed up the large integer calculation in RSA key generation and data encryption/ decryption process, so as to improve the efficiency of a RSA system. The RSA digital signature algorithm and its mathematic foundation are discussed in detail and the feasibility of RSA algorithm is proved. An integrated large integer library is built by using C++ and the implementations of Miller-Rabin, extended Euclid and Montgomery algorithms for complex numeric operations in RSA are given.