Applications Of Digital Signature In Credit Card Security

As electronic currency, Credit card appeared in early days of 20th century. In less than 100 years, Credit card has become fashionable all over the world for its particular advantage. With the wide application of Credit card, its security becomes more and more important. The bilk about Credit card occurs repeatedly and induce enormous expense . According to the statistic made by international organization VISA, the damage resulted from Credit card all over the world is 16 Hundred million dollars only in 2002, in which tenth occurred in Asia. This article brings forward an application of a new encryption algorithm and secret hash digital signature that aim at the insecure factors. At the base of these algorithms we can realize the secure Credit card system, which can accelerate the development of Credit card.In this paper we firstly discuss the general concepts of applied cryptography, and then introduce the mostly used modern encryption methods and technologies. We analyze the advantages and disadvantages of symmetric algorithm and public-key algorithm., bring forward a new block algorithm ?permutation code and secret hash digital signature . we describe the applications of these algorithms in Credit card .,which can reduce the damage induced by Credit card bilk. Permutation code broke through the traditional concept of block algorithm, and improved the encrypt intensity greatly. The secret hash digital signature is a new signature method that combines the ideas of RSA public-key algorithm, MD5 one-way hash function and permutation code at the same time, which is more secret, occupies less space and runs in higher speed.