【作者】 洪璇；

【导师】 陈克非；

【作者基本信息】 上海交通大学 ， 计算机系统结构， 2008， 博士

【摘要】 随着计算机和网络通信技术的发展,数字签名技术得到了广泛的应用。国内外众多学者对数字签名的理论、技术和应用进行了深入的探讨与研究。通用可组合安全框架(Universal Composability Framework)因其能简化协议的分析并提供更强的安全性而越来越受到人们的重视。然而就我们所知,对于UC安全框架下数字签名的研究还很少。比如,有一些签名体制的理想功能(Ideal Functionality)定义中所用到的假设欠缺合理性,还有一些签名体制的UC安全模型的研究尚为空白。本文针对UC安全框架下的门限签名体制、代理重签名体制、代理签名体制进行了系统的研究与设计,并取得了相应的研究成果。1.现有在UC安全框架下的门限签名体制的研究还不成熟,其理想功能并不完善,因此UC安全的门限签名协议的研究非常有意义。我们为门限签名定义了更为准确的理想功能,并构造了一系列满足UC安全的协议,包括两个门限签名协议和两个前摄性门限签名协议。我们提出的协议不仅具有可证明安全性,还满足UC安全性,弥补了已有相关工作中的不足,完善了UC安全框架下门限签名模型的研究。2.代理重签名体制是现代密码学一个新兴的研究领域,然而目前并没有满足UC安全的代理重签名方案。我们将UC安全框架引入到代理重签名体制中,提出两个具有UC安全性的简单有效的代理重签名方案。我们不仅完善了代理重签名基于游戏的安全模型,还首次给出其基于UC安全框架下的安全模型,为以后研究UC安全的代理重签名协议的工作铺平了道路。3. UC安全框架下的代理签名协议是研究的空白领域,因此我们进一步将UC安全框架扩展到代理签名体制中,构造了两个满足UC安全的代理门限签名协议。我们还针对资源受限的环境,探讨了如何设计适应于移动代理系统的代理多次签名方案和密钥隔离代理签名方案。我们的方案能在随机预言机模型下证明其安全性,并在一定程度上解决移动代理滥用和密钥泄漏的问题。对代理签名的安全模型所作的工作,是形式化分析代理签名体制的基础。更多还原

【Abstract】 Along with the development of computer and network technologies, digital signaturehas been widely used in people’s daily lives. Lots of international experts and scientistsfocus on the studies of digital signature’s theories, technologies, and applications. UniversalComposablity (UC) framework getting more and more attention dues to it can simplify theanalysis of protocols and provide more powerful security. As we know, the researches ondigital signature under the UC framework are very rare. Moreover, many digital signatureschemes are without reasonable assumptions of the definitions of ideal functionality, andsome protocols lack the analysis under the UC framework. This paper involves our studiesand designs of threshold signature, proxy re-signature and proxy signature under the UCframework. Our contributions are shown as follows:1. The current researches on threshold signature under the UC framework are far fromenough, and the ideal functionality is imperfect. Therefore, the studies of UC securethreshold signature schemes have significant values. We provide a more precise defini-tion of the ideal functionality for threshold signature primitive, and reconstruct a seriesof protocols, including two threshold signature protocols and two proactive thresholdprotocols, which are secure under UC Framework. The proposed protocols are notonly provably secure, but also secure under the UC framework. Our works comple-ment the shortage of the former researches, and better the researches on the formalstudies of the UC-based secure models for the threshold signature primitive.2. Proxy re-cryptography is one of the fresh topics in modern cryptography. As far aswe know, there is no UC secure proxy re-signature scheme. We first introduce the UCframework to the studies of proxy re-signature, and propose two efficient proxy re-signature schemes with the UC security. We not only further perfect the game-basedsecure model for the proxy re-signature primitive, but also give its UC-based securemodel for the first time. Our works pave the way for the future works on studying theUC secure proxy re-signature protocols. 3. There is little work on UC secure proxy signature nowadays. We extend the UC Frame-work to the proxy signature scenarios, and propose two UC secure proxy thresholdsignature protocols. Furthermore, we design the multi-times proxy signature schemeand key-insulated proxy signature scheme which are suitable for mobile agent system.These schemes are provably secure under random oracle model, and efficiently solvethe abuse of mobile agent and key exposure problem. Our works formalize the securemodel for the proxy signature primitive, which lays foundation of future works.更多还原