Based On Improved Research And Application Of Digital Signatures

With the fast development of the network, the security of Electronic Commerce is becoming a more important subject in our informational society. If the suitable means of guaranteeing the network security of Electronic Commerce is adopted, which have been studied, the datum transmission by the internet will be secure and reliable. In this way, an environment orderly of Electronic Commerce will be obtained. At present, techniques of cryptography are playing an important role in protecting the security of information in network efficiently. Digital signature is one of important techniques of security in cryptography, and blind signature is a type of especial digital signature. Now, it has being been the focus in security fields of Electronic Commerce that how to make the network information secure efficiently by using digital signature and special digital signature. In this paper, after studying the techniques of digital signature and blind digital signature, two improved algorithms about digital signature and blind digital signature was presented. And then, these algorithms were applied in Electronic Cash system, it will make it more secure and practical to trade in Electronic Commerce.The whole paper is organized as follows. Firstly, the cryptosystem,principles and algorithms were introduced. Then, combining with the knowledge of digital signature , based on cryptography of public key, and Hash function, a improved algorithms of digital signature based on ElGamal Public Key system is proposed. After compared with three traditional algorithms of digital signature, the description of the advantages,disadvantages and security on the improved algorithms was discussed.Finally, after studying the blind digital signature, the other improved algorithms of blind digital signature based on ElGamal Public Key system is given, and its property is also analyzed in detail. According to the present situation of the Electronic Cash, a new controlled anonymous off-line Electronic Cash system is formed with the two improving algorithms above, in which how to use the system is described.Through proving,analyzing and comparing, two conclusions can be obtained. The one is that the improved algorithms of digital signature based on ElGamal is more secure,efficient and easier while carrying on. The other is that the improved algorithms of blind digital signature based on ElGamal is also more secure. Because it is known clearly that who is signer or the requester to obtain a signature, it is much easier to resume the signature for the original information from the signature of the blind information. At same time, through analyzing the property and comparing the efficiency of the new Electronic Cash systenra controlled anonymous off-line E-Cash system, it shows that the system is better in security, anonymity, controlled anonymity,non-repeatability and unforgeability than the existing system. Hence, this system is very useful for many Electronic commerce applications.