【作者】 宋考；

【导师】 周洲仪； 谢冬青；

【作者基本信息】 湖南大学 ， 计算机软件与理论， 2006， 硕士

【摘要】 群签名方案是一种用处广泛的签名形式,到目前为止,在所提出的签名方案中,ACJT方案是各种性能最好的方案,它满足了常见的安全需求,同时抵制了已经出现的各种攻击方法,因此本文以此方案为基础,研究了特殊环境下的特殊需求,给出了三种特殊的群签名。首先,在电子商务等实际应用场合中,需要保持匿名性,即任何人使用电子货币后,不能被跟踪,盲签名可以满足这种安全属性,而群签名又常常用在电子银行的实现方案中,因此群盲签名可以满足这两个需求,因此本文在L.Anna和R.zulfikar提出的一个盲化的双离散对数协议的基础上,基于ACJT方案实现了群盲签名。另外,在电子银行中,群密钥是整个系统的最核心机密,如果群密钥泄露,整个系统将被破坏,为了降低此类风险,把损失降到最低,将前向安全的概念引入到群签名中,当某个时间段密钥泄露后,这个时间段以前所做的签名文件、加密文件等不会被破坏,因此,这样就极大地扩展了群签名的安全属性。在普通的签名系统中,签名文件是可以无限验证的,即每个人都可以通过群公钥来验证其有效性,但在某些特殊领域,尤其是电子银行业务中,这样广泛的验证人群在某些情况下是不合适的,有时,某些特殊的签名文件只能有某些指定的验证者进行验证,本文在ACJT方案的基础上,根据通用的指定验证者的方案构造了指定验证者的群签名方案。在上述方案的基础上,本文初步实现了多银行系统,完善了以前方案的缺陷,解决了电子现金的面值问题,它可以由发行行指定,并且和盲签名有效地对应起来,这样就保证避免用户欺诈问题。更多还原

【Abstract】 Group signature is one of the useful singnatures,by now ,in all the schemes,ACJT is the best in all kinds of capabilities,as it satisfies the common security requirements,at the same time,it resisits all the attack ways.This paper reviews the requirements in special setting,then provides 3 types of group signature.Firstly,in the electronic commerce,it needs the anonymity,when one use the electronic coin,he could not be tracing,blind signature can satisfy the security requirement,and Group signature is often used in electronic bank scheme,so group blind signature can satisfy all these security requirements.with the protocal of blind bidiscrete logarithm proposed by L.Anna and R.zulfikar,this paper implements the group blind signature on the ACJT scheme.Secondly,in the electronic bank system,the group key is the core secret,once the key is leaked,the whole system will be destroyed.for the goal of reducing risk,this paper adds the concerp of forward-security to group signature.when the key in one time segment is leaked,the document signed or encrypted befor this segment can nor be destroyed.So that it greatly extends the security of the group signature scheme.In the common signature system,the signed document can be verified illimitably,anyone can verifies its validity with the group key.but in some special setting,large numbers of verifier are not appropriate,sometimes document can only be verified by some designated people.This paper proposes the designated-verifier group signature scheme with the UDVS on ACJT.At last this paper implements the multi-bank system with above schemes,remedies the limitation of forgoing schemes,and resolves the par value problem.The par value is designated by the bank,and it is binding with the signature,thus the problem of user cheating can be avoided.更多还原