Development Of Group Signature And The Research And Application Of Group Signature Schemes

With the rapid development of Information Science and Technology and the prevalence of network, digital signatures find more and more application in each realm of our society. Digital signature can solve How to sign rapidly in case of long distance in stead of handwritten signature or seal. Group signature is an important type of signature. Group signature is proposed by D.Chaum and E.van Heyst in 1991 .It can allow any member of the group to sign on behalf of the group. Anyone who know the public key of the group is able to verify whether the signature is legitimate or not,but he can not know who sign it. If any dispute,there is group manager who can open the signature to reveal the identity of the actual signer.As group signature is anonymous, safe and is able to be opened when needed,it can be used in electronic voting, electronic bidding, untraceable electronic cash system ,etc.However,security and efficiency can not look after both sides in existing schemes. Therefore the application research is still in a theoretical investigation stage. There are some limitations such as low efficiency in member joining or revocation, forward insecurity,etc.These made group signature hard to use in large group. Thus proposing secure group signatures with high efficiency and analyzing existing group signature schemes are two important directions in group signature field.When we propose a new group signature scheme,we use tools such as RSA signature algorithm ,Elgamal signature algorithm ,knowledge proving. And our scheme is based on some number-theoretic assumptions. Our research results:1 Reviewed the process of the development of group signature,analyzed several important group signature schemes.2 We proposed a security flaw of a group signature scheme based on RSA signature scheme. We proved that this scheme is insecurity. We also improved it and our improved scheme is secure forward,dynamic.3 A security flaw is identified in a dynamic group signature .The analysis of the security flaw is proposed.4 We overviewed applications of Group signature in Electronic Cash System.