【作者】 吴涛；

【导师】 彭代渊；

【作者基本信息】 西南交通大学 ， 密码学， 2010， 硕士

【摘要】 当前,网络通信技术及计算机技术的迅速发展给人们的工作和生活带来了巨大变革,电子商务、电子政务等信息化活动已成为经济生活的核心组成部分。作为信息安全技术中一种主要的认证手段,数字签名得到了广泛的应用。最初的数字签名仅被用于在电子传输中提供数据的认证性、完整性和不可否认性,但基本的数字签名并不总能满足实际应用中的不同需求,因而产生了在特定应用背景下的具有特殊性质的数字签名形式,如盲签名、群签名、环签名等。环签名是一种简化的类群签名,它克服了群签名中群管理员权限过大的缺点,对签名者是无条件匿名的。它所具备的性质如自发性、无条件匿名性和群特性对于构建电子商务、电子政务等系统方案有着特殊作用,因此对于环签名方案的研究有重要的理论和实际意义。电子支付系统是电子商务的核心组成部分,其实现和发展程度一直是影响电子商务发展速度的主要因素之一。电子现金作为传统现金在信息化空间的模拟,具有其它电子支付方式所不可比拟的优势,从而成为电子商务网络支付技术的首选技术。电子现金的安全性和匿名性都是靠密码技术来实现的,已有电子现金协议的设计大多基于盲签名和群签名设计,而环签名以其良好的特性成为电子现金协议设计中的重要手段之一。本文针对环签名的特点,对如何构造可适用于电子现金的环签名方案进行了深入研究。本文主要内容如下：1.首先介绍了与本文相关的密码学理论基础,包括数论基础、数学困难问题和数字签名的相关知识；简要总结了环签名和电子现金的研究发展状况。2.介绍了环签名的基本原理和安全特性,分析和总结了环签名方案的设计方法；指出特殊数字签名技术是电子现金应用的关键技术之一,并简要介绍了几种特殊数字签名及其应用前景。3.对基于身份的环签名方案进行了分析,给出了一个改进的的基于身份的环签名方案；重点对关联环签名方案进行了研究分析,对基于身份的关联环签名进行了改进,提出了一种可追踪关联环签名方案,该方案基于双线性对实现,与传统关联环签名相比,减少了双线性对的计算消耗,提高了运算效率,实现了对重复签名者身份的追踪,更好地满足了电子现金的应用需求。4.为了保证特殊需求下的电子现金协议的安全性,基于已有环签名和盲签名方案,设计了一种安全高效的电子现金协议,与之前的电子现金协议相比,该协议充分利用了环签名的性质,实现了对重复花费行为的事前检测,并在撤消匿名性的情况下可追踪重复签名人的身份信息。更多还原

【Abstract】 Currently, the rapid development of the computer technology and network communication brings people’s work and life great changes. E-commerce, E-government and other information activities have become a core component of economic life. As a primary means of authentication in Information security technology, digital signature has been widely used. The first digital signature is only used in the electronic transmission of data to provide data authentication, integrity and non-repudiation. The basic digital signature does not always meet the different needs of practical applications, thus the special nature of the digital signature forms was generated in the context of specific applications, such as the blind signature, group signature and ring signatures.As a kind of simplified group signatures, ring signature overcomes the disadvantage that the right of the administrator in group signatures is too large, and the signer is unconditionally anonymous. Its spontaneous, unconditional anonymity and group characteristics has a special role in building E-commerce, E-government system. Therefore, the research for ring signature scheme has important theoretical and practical significance.Electronic payment system is a core component of E-commerce, its implementation and level of development has been the impact of E-commerce growth rate of the main factors. As an analog of traditional cash in the information space, with incomparable advantages than other E-commerce payments E-cash become the preferred technology in E-commerce online payment technology. The security and anonymity of E-cash are achieved by cryptography, the existing electronic cash protocols have been designed mostly based on blind signatures and group signatures. The ring signature with its good features is one important means in electronic cash protocol design. This paper focuses on how to construct ring signature scheme that can apply to electronic cash protocol.This paper has conducted the following works:1. Firstly, we have introduced the basis cryptography theory that associated with this article, ranging from basic number theory, mathematical difficulties and knowledge of digital signatures; then briefly summary of the ring signature and e-cash research and development status.2. Secondly, we introduce the basic principles and security features of ring signatures, analyze and summarize the method of ring signature scheme design; and also point out that a special digital signature technology is one of the key technologies of the E-cash applications. outlined several specific digital signatures and their application.3. Identity-based ring signature scheme is analyzed and an improved identity-based ring signature scheme is designed; we focus on the linkable ring signature scheme, and improve the identity-based ring signature, and propose a kind of traceability linkable ring signature scheme. The scheme is based on bilinear pairings. Compared with the traditional ring signature, it decreases the calculation of pairing consumption, and realizes the function of repetitive tracking. It is better meet the needs of the electronic cash applications.4. To ensure the special needs under the security of electronic cash, based on the existing ring signature and blind signature scheme, we design a safe and efficient electronic cash system. Compared to the previous electronic cash protocol, the protocol use better of ring signatures features to achieve double-spending behavior of pre-testing, and is able to track the signer’s repeat identity information in the case of withdrawal of anonymity.更多还原