【作者】 程艳；

【导师】 傅鹂；

【作者基本信息】 重庆大学 ， 计算机软件与理论， 2006， 硕士

【摘要】 盲签名是一种特殊的数字签名,在有匿名性要求的网络通信中具有独特的地位和作用。特别地,在电子现金系统中,避免了银行与商家勾结通过现金消费跟踪用户的消费记录,从而维护用户的隐私权;在电子选举中,切断了投票者与选票之间的关系,对选举管理机构隐藏选票内容,实现无记名投票。目前,已经有一些电子现金系统(DigiCash和NetCash)、电子选举方案开始使用,其中大多数都是为了满足安全需求,真正大规模的、能应用于Internet的方案还很少,国内这方面的工作还处于探索阶段。这主要是由于这些应用中的关键技术——盲签名方案的设计比较复杂,还存在安全性不高、签名验证效率低和计算量大等不足。随着电子商务和电子政务的蓬勃发展,急需安全、高效、适用的盲签名方案。本文从安全性、实现效率、运算量等方面深入分析现有的典型盲签名方案后,研究提出“基于椭圆曲线密码体制的XML盲签名”及其实施方案。主要是基于如下两个事实:第一,可扩展标记语言(eXtensible Markup Language,XML)被越来越多地用作电子商务、电子政务中数据交换的标准格式,从根本上解决信息孤岛问题;第二,椭圆曲线密码体制(Elliptic Curve Cryptography,ECC)受到越来越广泛的关注,其“短密钥,高安全”的固有特性胜过RSA、DSA等现行密码体制。该方案结合XML和ECC的优势,在保护用户匿名性的同时,提高签名验证效率,保障信息的高安全性,对设计适用于电子商务、电子政务领域的盲签名方案作出了探索。本文的主要工作及成果包括:首先,为保证更高的安全性,本文基于椭圆曲线密码体制研究现有的盲签名算法,改进了其中影响签名验证效率的关键算法——多点乘算法,给出了整体运算效率较高的椭圆曲线盲签名算法(Elliptic Curve Blind Signature Algrithm,ECBSA)。其次,通过将XML数字签名技术延伸到盲签名,并以上述椭圆曲线盲签名算法为基础,本文给出了基于椭圆曲线密码体制的XML盲签名方案,并证明了该方案的有效性和安全性。最后,对提出的方案进行实现,并使用已证明安全的素数域上的随机椭圆曲线进行实验,结果表明:(1)改进的多点乘算法适用于基于椭圆曲线密码体制的XML盲签名方案,能够有效地节省运算开销,提高方案的整体实现效率;(2)相对于其他公钥密码体制,使用椭圆曲线密码体制更能确保方案的高安全性、更有利于盲签名方案的应用与推广。更多还原

【Abstract】 Blind signature is a special kind of digital signature, which has particular status and effect in network communication requiring anonymity. Especially, it protects users’anonymity in E-cash systems from tracking consume records by banks and merchants; and cuts off voters relations with electronic ballots in E-voting systems for secret ballots which are secret to voting management organization. Although several E-cash systems, such as DigiCash and NetCash, and E-voting systems have been used at present, most of them only satisfy security requirement and real large-scale one applied on the Internet is infrequent. Moreover, domestic research about this is at exploring stage. Because that the design of blind signature schemes, which is the key technology in those systems, is complex and these schemes haven’t high security, high efficiency of validation and small operation counts. With the fast development of E-commerce and E-government, blind signature schemes are needed urgently which are secure, efficient and applicable.This paper proposes“an XML Blind Signature Based on Elliptic Curve Cryptography”and its implementation scheme, after analyzing the current typical blind signature schemes on security, efficiency and operation counts. There are two reasons for this. One is that eXtensible Markup Language (XML) is adopted by more and more applications of E-commerce and E-government as the standard format of exchanging data. The other one is that Elliptic Curve Cryptography (ECC) is concerned widely and is better than RSA and DSA because of its“small size, high security”. Combining the merits of XML and ECC, the scheme improves signature validation efficiency, insures high security and protects anonymity as well, which do some exploration for applicable blind signature schemes in E-commerce and E-government.The main work and archivements of the paper are as following:Firstly, for higher security, the paper presents an Elliptic Curve Blind Signature Algorithm (ECBSA) based on current similar algorithms. It has high operating efficiency through improving multiple point multiplication algorithm, which is the key algorithm effecting signature validation. Secondly, an XML blind signature scheme based on ECC is proposed using XML digital signature and ECBSA above, and its validity and security have been proved. Lastly, the new scheme is implemented and tested using random elliptic curve over prime fields. The results show that: (1) The更多还原