【作者】 高虎明；

【导师】 王育民；

【作者基本信息】 西安电子科技大学 ， 密码学， 2002， 博士

【摘要】 计算机通信网特别是Internet的广泛普及给人类社会的生存方式带来了深刻的革命。数字化社会里很多应用领域需要保护信息的源和宿的秘密性,及进行匿名通信。随着数字化网络化的发展电子商务逐步代替传统商务,电子支付是实现电子商务的关键技术,具有保证支付者匿名的电子现金是电子支付手段中不可缺少的方式。学者们对它们已进行了20 多年的研究,目前已有一些实用的匿名通信系统和电子现金系统在运行。Mixes net 技术是适用于Internet 上实现匿名通信的很好手段,eCashTM 是Internet 上最早实现的使用的电子现金系统,它们都需要进一步完善和改进。本文总结分析了匿名通信和电子现金研究领域的成果和进展,对匿名性通信理论做了一些完善,提出了Mixes net 和电子现金的改进方案。我们主要进行了以下工作: 1. 总结介绍了实现匿名通信的技术、提供匿名通信服务公司和研究项目; 2. 总结和研究了匿名性的定义和度量,提出了用互信息量度量发送者与接收者的无关联性的方法,有助于判断和设计安全的匿名通信系统; 3. 总结回顾了Mixes net 的研究进展,建立了(t,N-2)Mixes net 模型,设计了一个新的基于这个模型的高效的Mixes net 协议,具有可验证性和(t,N-2)弹性; 4. 利用以上(t,N-2)Mixes net 协议设计了一个新的安全电子投票方案,保证了选票的秘密性、选票的唯一性、选举的完整性、投票者的匿名性、选票的可公开性、选举的可验证性; 5. 概括介绍了电子现金的概念、分类、实现方法和使用状况,讨论了电子现金的发展前景和尚需解决的一些问题; 6. 指出了eCashTM 系统的两个缺陷,提出了与原方案等效的能避免这些缺陷的一个在线完全匿名的实用电子现金系统改进方案; 7. 提出了一个脱线可控制匿名的对eCashTM 系统改进的高效实用电子现金系统方案。更多还原

【Abstract】 Computer networks especially Internet are widely used in the world. It has been greatly changing our daily life. The sender and receptor for a certain message should be kept secret in many applications. Anonymity communication is essentially needed in the digital world. Electronic payment systems are essential tools for E-commence. Electronic cash will play an important role in the future due to its unique anonymity property. There are many practical systems that provide anonymous communications for Internet users and electronic cash systems in operation after about 20 years academe study in the literature of anonymity communication and electronic cash. Mixes net technology is used as a basic tool in anonymity communication systems. eCashTM is the first employment electronic cash system in the world. We focus on the fields of anonymity communication and electronic cash in this dissertation. Our main contributions is listed as following: 1. An overview of current techniques, deployment and research project of anonymity communication is present; 2. A new method for measuring sender and receptor’s unlinkabilty is given which can be used to judge a anonymity communication system; 3. A new (t,N-2)-resilience verifiable Mix net protocol is proposed using the primitive cryptography tools of Shamir secret share scheme, ElGamal public key system, zero-knowledge and so on . Its communication cost and computing cost is less than other verifiable Mix net that we know presently; 4. A secure electronic voting scheme based on the new Mix net is designed. Our scheme has the properties: vote privacy、fairness、publicity, voting public verifiability、and voter’s anonymity simultaneously; 5. The notion, design, deployment and application of electronic cash is summarized. Some open problems in the field are present; 6. Two flaws in the eCashTM system are pointed out. A new improved applicable system for eCashTM is given that has the same efficiency with eCashTM and also overcomes the flaws; 7. An off_line revocable anonymity eCashTM like efficient applicable system is designed .更多还原