Construction On Dynamic Group Signature Scheme And Group Blind Signature Scheme

Since the concept of digital signature was proposed by Diffie and Hellman, digitalsignature technique has been deeply studied by researchers and has been widely used innetwork now. Besides the research of traditional digital signature, researchs on blind signature,threshold signature, proxy signature have been made also. This paper focuses on groupsignature. In group signature schemes, group members can anonymously sign a document onbehalf of the group. In case of dispute, the group manager can open the signature to reveal theidentity of the signer. In contrast with other digital signatures, group signature has anonymityand traceability, which makes it have wide applications in electronic commerce, such aselectronic auction and electronic cash.For group signature schemes to be applicable to reality, it must be able to successfullyadd new members and remove group members. Therefore, many experts and researchersstudy the problem to make existing group signature schemes with dynamic. There are manystudies for the combination of group signature and the traditional digital signatures, such asproxy group signature, threshold signature, group blind signature, and so on.This paper is devoted to the application of vector space secret sharing group signaturescheme and group signature scheme based on the Chinese remainder theorem, aiming at theflaws in the group signature schemes, three group signature schemes are put forward. Thispaper obtains main contributions as follows.Firstly, this paper analyzes the group signature scheme suggested by Zhao Shuping andfinds this scheme do not have dynamic nature. According to the vector space secret sharing, adynamic group signature scheme based on bilinear pairing is proposed, in this scheme, givena secret, when add or remove members of group, the sub-secret of each member have beenchanged. Analysis shows that this scheme is secure. Besides, this scheme has also improvedthe efficiency of the original signature scheme.Secondly, electronic auction is electronization of a real auction system, electronicauction is also one of the most important application about e-commerce. In order to improve the efficiency and security of the electronic auction, a new electronic auction scheme isdesigned based on the group signature. The scheme is based on bilinear pairing, in whichvector space secret sharing and subliminal channel are used. The scheme is designed on thebasis of the dynamic group signature based on bilinear pairing. The scheme is suitable forlarge scale distributed aution, furthermore, the scheme is also secure and efficient.Thirdly, group blind signature is a special signature by combining group signature andblind signature, which meets all advantages of both group signature and blind signature. Thisthesis analyzes the group signature scheme based on Chinese remainder theorem suggested byLi Xinshe, and finds that this scheme does not have security nature against framing attack:group center can frame each group member to signature. Aiming at this flaw, this paperproposed a forward secure group blind signature scheme which adds the nature of forwardsecurity and blind signature. The analysis of security shows that improved scheme hasforward security nature and is secure against framing attack and with unforgeability and othersecurity nature which group signature requires, at the same time, group member can signaturewithout revealing any information about the message.