Research On Proxy Signature Scheme

With the development of the Internet, the human society’s reliance on the networkgradually increased. At the same time, the network security becomed more importantcryptology. The basic objective of cryptology is achieving information integrity,authentication and nonrepudiation, usability and so on. Among them, privacy andauthentication are two important aspects of the information security. Digital signature isthe primary method to provide the authentication, it also is one of the important aspect ofresearch of modern cryptology.With the demand of application increasing, the basic digital signature schemes cannot meet the needs of some applications, and some digital signature schemes whichpossess certain characteristics are required, the proxy signature scheme is one of theseschemes. Proxy signature is first proposed by Mambo et al. In 1996. In a proxy signaturescheme, an original signer is allowed to delegate his signing poeer to a designed per orgroup, who is called the proxy signer and can sign messages on behalf of the originalsigner.Firstly, this paper analyzes the security of the forward-secure proxy signaturescheme based on discrete logarithm suggested by Mambo et al.and points out it is notsecure. Finally, a new scheme is proposed and its security is analyzed.Then, this paper presents the basic concept and related knowledge of elliptic curveproxy signature, discusses the present situation of the forward security. It achievespreventing artificial private key leak. And this paper proposes a new proxy signaturefrom bilinear pairings. Its security is analyzed and the result shows that this scheme issecure and effective, it can effectively resist the forgery attacks and satisfy the securityproperties of strong proxy signature. Compared with other schemes, the new scheme hasbetter computational efficiency.Lastly, this paper gives the security analysis of the blind signature scheme of Guli-ze et al. with the method of construction, we point out that this scheme exists a somesecurity risks in some aspects. Associating with the features of proxy signature and blind signature, Conducive to multiple linear relationship. A ECDLP-based proxy blindsignature scheme was proposed. Security of the new schemes is analyzed. It is concludedfrom the analysis that this scheme has a good properties such as verifiability,distinguish-ability, blindness, etc. The new proxy blind signature scheme is of moresecurity and higher efficiency.