摘要
The EIGamal algorithm, which can be used for both signature and encryption, is of importance in public-key cryptosystems. However, there has arisen an issue that different criteria of selecting a random number are used for the same algorithm. In the aspects of the sufficiency, necessity, security and computational overhead of parameter selection, this paper analyzes these criteria in a comparative manner and points out the insecurities in some textbook cryptographic schemes. Meanwhile, in order to enhance security a novel generalization of the EIGamal signature scheme is made by expanding the range of selecting random numbers at an acceptable cost of additional computation, and its feasibility is demonstrated.
The EIGamal algorithm, which can be used for both signature and encryption, is of importance in public-key cryptosystems. However, there has arisen an issue that different criteria of selecting a random number are used for the same algorithm. In the aspects of the sufficiency, necessity, security and computational overhead of parameter selection, this paper analyzes these criteria in a comparative manner and points out the insecurities in some textbook cryptographic schemes. Meanwhile, in order to enhance security a novel generalization of the EIGamal signature scheme is made by expanding the range of selecting random numbers at an acceptable cost of additional computation, and its feasibility is demonstrated.
基金
Supported by National Natural Science Foundation of China (No. 60272011) and the Special Fund for Cultivating Excellent Scholars of Beijing Municipality (No.20042D0500103)
作者简介
YANG Jun （杨军） was born in Chongqing, China, in 1963. He received the B.Se. degree in mathematics from Southwest China Normal University in 1985 and the M.S. degree in applied mathematics from Siehuan University in 2002. He is currently a Ph.D. candidate majoring in computer applications at University of Science and Technology Beijing and an associate professor with Fuling Normal College. His research interests include applied cryptography, multieast security and group key management.ZHOU Xian-wei （周贤伟） was bom in Sichuan, China, in 1963. He is currently a postdoctoral researcher with the School of Information Engineering, University of Science and Technology Beijing. He has published more than 50 papers in important academic journals. His research fields include communication network security, broadband mobile communications and multieast security.QIN Bo-ping （覃伯平） was bom in Sichuan, China, in 1971. He received the B.Sc. degree in mathematics from Southwest China Normal University in 1993 and the M.S. degree in management from Beijing University of Aeronautics and Astronautics in 2002. He is currently a Ph.D. candidate majoring in computer applications at University of Science and Technology Beijing. His research interests include applied cryptography, network security and sensor networks.
