A Novel Modular Multiplication Algorithm and its Application to RSA Decryption

The services such as electronic commerce, internet privacy, authentication, confidentiality, data integrity and non repudiation are presented by public key cryptosystems. The most popular of public key cryptosystems is RSA cryptosystem. RSA is widely used for digital signature and digital envelope, which provide privacy and authentication. The basic operation of RSA cryptosystem is modular exponentiation which is achieved by repeated modular multiplications. RSA can be speeded up by using the Chinese Remainder Theorem (CRT) and using strong prime criterion. In this paper, we present an efficient modulo n multiplication algorithm with reasonable factors of 2n and 2n+2. In this paper we discuss decryption techniques in RSA cryptosystem. We show that this new technique can speed up the decryption process and it can reduce the computational time compared to the methods of traditional, CRT, and Hwang et al.[10] .