REDUCED TIME COMPLEXITY VARIANT OF DIGITAL SIGNATURE ALGORITHM

摘要

Signing and verification time of messages is an essential issue. The standard Digital signature algorithm (DSA) approved by the national institute of standard and technology (NIST) has been widely used for message authentication. Besides, many variants of DSA has been suggested in order to improve the performance, such as Yen-Laih, GOST, McCurley, and other algorithms. This paper present a modified version of the standard NISI-DSA. It incorporates the same parameters used in NISI-DSA, but it is characterized by less computational complexity and improved signature verification time which is crucial for some sensitive applications. This variant achieved an increase in the verification speed of about 100% over most DSA variants, hence reducing the signature validation time considerably, however, no improvement was noticed in the signing speed. This signature validation speed gain was achieved with the same level of security as the parameters of standard DSA were used. The algorithm is first tested with prime numbers of 20, 40, 80, and 100 bits lengths, then it is experimented with using prime numbers provided by NIST with length of 1024 bits and 128 bits for p and q, respectively. The speed of verification results shows more than two times faster than NIST-DSA.