期刊名称：International Journal of Computer Trends and Technology
电子版ISSN：2231-2803
出版年度：2013
卷号：4
期号：9-4
出版社：Seventh Sense Research Group
摘要：Most digital signature schemes have the common feature that they are based on a single cryptographic assumption, like integer factorization problem (IFP) or discrete logarithm problem (DLP). For example, RSA scheme is based on the IFP, and ElGamal scheme is based on the DLP. So far, these hard problems still cannot be solved efficiently and we believe that the schemes are secure. However, if these problems can be solved by an efficient method in the future, the associated cryptographic scheme will no longer be secure. Thus, people try to enhance the security of cryptographic schemes by constructing them based on multiple hard problems simultaneously. Recently, S. Vishnoi and V. Shrivastava proposed a new signature scheme which is based on factorization and discrete logarithm problem, denoted as V & S scheme in this paper. S. Vishnoi and V. Shrivastava claimed that their scheme is secure and its security is based on the difficulty of computing factoring and discrete logarithms. In this paper, we show that this scheme is not secure and is not based on any hard problems; a simple attack is given.
