【作者】 崔涛；

【导师】 刘培玉；

【作者基本信息】 山东师范大学 ， 计算机应用技术， 2013， 硕士

【摘要】 随着因特网的飞速发展，网络通信成为人们交流的主要方式之一。因此，网络信息安全问题受到越来越多的关注。数字签名作为确保网络信息安全的核心技术之一，在理论研究和现实生活中都发挥着十分重要的作用。在日常生活中，人们可以将印章交给自己信任的人，让其代为行使签名权；但是在信息社会中，普通的数字签名无法使用类似的方式委托签名权。为了解决上述问题，Mambo等人提出了代理签名，一种带有授权机制的数字签名。随着代理签名理论研究的不断深入和现实需求的不断变化，一些具有特殊性质的代理签名方案越发受到人们的青睐。本文主要对指定验证者(t, n)门限代理签名和具有前向安全特性的指定验证者代理签名进行了探讨和研究，现将所做工作总结如下：1.简要回顾了代理签名的研究背景、意义和现状；介绍了代理签名的相关数学知识、概念、性质、分类以及前向安全和门限秘密共享的思想；回顾了几种经典的代理签名方案，并且对其进行了简要的安全性分析；2.对一种已有的(t, n)门限代理签名方案进行了回顾和分析，指出其中存在的安全缺陷并且提出了改进方案；然后在改进方案中加入指定验证者，设计了一种指定验证者(t, n)门限代理签名方案。性能分析表明：改进方案一克服了原方案中的不足，改进方案二在效率方面有了一定提高，两种改进方案均满足代理签名的各种安全性要求；3.为了减小密钥泄漏的损失，将前向安全引入代理签名中，提出一种前向安全的指定验证者代理签名方案；然后将前向安全引入门限代理签名中，提出一种前向安全的指定验证者(t, n)门限代理签名方案。性能分析表明：两种方案均实现了前向安全。新方案一具有较高的执行效率，新方案二的设计中没有可信中心，提高了自身安全性；签名具有消息恢复的特性，减小了传输签名时的通信代价。更多还原

【Abstract】 With the Internet’s rapid development, network communication becomes one of people’smain ways to communicate. So the network information security problem receives more andmore attention. Digital signature, one of the key techniques to ensure the network informationsecurity, plays an important role in both theoretical research and real life.In everyday life, people often delegate their signing rights to reliable agents by passingstamp. But in information society, common digital signature can’t delegate the signing right in asimilar way. To solve the above-mentioned problem, Mambo et al. put forward proxy signature, adigital signature with authorization mechanism. With the deepening of the theory research andthe constant change of the real demand, some proxy signature schemes with special propertiesreceive more and more people’s favors.This paper mainly aims at the designated verifier (t, n) threshold proxy signature and theforward secure designated verifier proxy signature. And the following is the work concludes.1. This paper firstly takes a brief look at the proxy signature’s research background,significance and the current situation. And then, it gives a brief account of some mathematicalknowledge, concept, properties, classification of proxy signature, reviews the basic ideas offorward security and (t, n) threshold. Finally, it reviews some kinds of classical proxy signatureschemes and gives brief security analyses.2. This paper reviews and analyzes an existing (t, n) threshold proxy signature scheme,points out its flaws and gives an improvement. Then, it integrates designated verifier into theimprovement to design a designated verifier (t, n) threshold proxy signature scheme.Performance analysis shows that the first improvement overcomes the original scheme’s flaws,the second has a certain increase in the efficiency, and both the two improvements satisfy all thesecure properties of proxy signature.3. To reduce the key exposure loss, this paper integrates forward security into proxysignature to come up with a forward secure proxy signature scheme with designated verifier. Andthen, it integrates forward security into threshold proxy signature to propose a forward secure (t,n) threshold proxy signature scheme with designated verifier. Performance analysis shows thatboth the two new schemes realize forward security. The first new one has high efficiency, thesecond has no trusted center, which improves its own security, and the signature has properties ofmessage recovery, which reduces the costs of the signature transmission.更多还原