论文标题:群签名体制的研究与设计
Study and Design on Group Signature Scheme
论文作者
论文导师 肖国镇,论文学位 硕士,论文专业 密码学
论文单位 西安电子科技大学,点击次数 203,论文页数 67页File Size873K
2006-01-01论文网 http://www.lw23.com/lunwen_381217217/
group signature; dynamic group signature; knowledge signature;ElGamal Encryption
群签名是数字签名中非常重要的一种类型,是由D.Chaum和E.van Heyst于1991年首次提出来的。它允许群成员代表群进行签名而不泄露群成员的任何信息。正是由于群签名方案中对群成员的匿名性,使之在电子选举、电子投标和离线电子货币等方面有着潜在的应用价值。本文主要研究了群签名的安全性问题、动态群签名方案的构造以及群成员的删除问题。本文的主要研究结果如下: ⒈对ACJT方案提出一种不需要伪造群成员资格证书的伪造攻击方法,即攻击者不需要伪造群成员资格证书,就可以直接成功伪造有效的群签名。进而针对所提出的伪造攻击,对该方案进行改进,改进方案中利用两个知识签名验证群成员资格证书和群成员私钥,结果表明改进方案能抵抗伪造攻击。 ⒉利用ElGamal加密和知识签名技术提出一种高效而且安全的动态群签名方案。该方案允许群管理员灵活得增加和删除群成员,并且群签名的长度以及签名、验证、打开算法的计算量独立于群成员数、已删除的群成员数。所以此方案更为高效,其安全性是基于RSA假设、ElGamal加密和知识签名的安全性。 ⒊用互素的知识签名构造了一个动态群签名方案,在这个方案中群管理员只需要在撤消群成员时利用简单的乘法运算更新群公钥,签名时合法的群成员只需要在签名过程中用互素知识签名证明自己是未被撤消的群成员。该方案中的签名和验证算法都独立于群成员数和被撤消的群成员数,因此非常高效。方案基于RSA假设和DDH(Decisional Deffie-Hellman)假设,是安全的。
Group signature which is a sort of important digital signatures, firstly introduced by D. Chaum and E. van Heyst in 1991, allowed individual members of a group to make signatures on behalf of the group while providing the signer’s anonymity. Owing to its anonymity, group signature can be applied in the activity of electronic politics and electronic commerce such as electronic voting, electronic bidding and off-line electronic cash and so on. In this thesis,we mianly study the security of group signature , the construction of dynamic group signature and the deleting problem of group members. The main results of this thesis are as follows: 1.We propose a forgery attack on the ACJT group signature scheme. By using the forgery attack, an attacker can forge a valid group signature without forging the group membership certificate. By identifying the forgery attack, we show that their scheme is insecure. Besides ,an improved scheme is proposed, in which two knowledge signatures are used to verify group membership certificate and group member’s secret key .And it’s proved secure against the forgery attack.. 2. An efficient and secure dynamic group signature scheme based on ElGamal Encryption and knowledge signature is proposed.It allows the group manager to increase or delete group members flexibly.Furthermore,the length of the group signature ,as well as the computational effort of signing,verifying and opening,are very small and independent of the number of the group members and the deleted group members.So this scheme is much more efficient,and its security is based on RSA assumption, the security of ElGamal Encryption and knowledge signature. 3. A dynamic group singnature based on co-prime knowledge signature is proposed. In this scheme the group member can update the group public key by simple multiplication.When compute signature, the valid group member can use co-prime knowledge signature to verify that he is not deleted. It’s very efficient and its security is based on RSA assumption and DDH assumption.
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