【作者】 赵洋；

【导师】 秦志光；

【作者基本信息】 电子科技大学 ， 信息安全， 2009， 博士

【摘要】 安全多方计算是现代密码学领域重要的研究内容之一。在分布式网络环境下,实现多方参与的安全协同计算是安全多方计算的核心研究问题。现有的大多数网络安全应用协议都可以规约为一个特定安全多方计算协议,因此安全多方计算吸引了众多研究者的关注。目前,安全多方计算研究主要集中在两个方面：一方面是针对安全多方计算基础理论的研究,包括安全模型及一般安全性定义研究,安全多方计算基础协议及通用设计方法的研究,协议安全性分析方法研究。取得的主要成果有,半诚实模型和恶意模型下严格的安全性定义,不同安全模型下安全协议的可行性结论,以及通用的安全协议设计方法等。另一方面,则是针对实际应用的安全协议研究,包括电子拍卖、电子选举、公平交换、基于隐私的数据查询等。取得的主要成果反映在提出了大量安全应用协议。尽管在理论研究和实际应用方面已经取得了不少的成果,但安全多方计算领域仍然有许多值得研究的内容。在基础理论方面,现有的安全模型和一般安全性定义,不能够反映不同应用问题的特点,更实用的安全模型需要进一步研究。使用通用的协议设计方法进行应用协议的设计,普遍存在着效率低下的问题,针对特定应用的协议设计方法值得进一步探讨。针对复杂协议的安全性分析还缺乏普遍认可的方法,需要进行更深入的研究。在实用安全协议设计方面,现有的应用安全协议还存在着可改进的空间,解决从应用中抽象出来的新问题,需要设计新的安全协议。基于上述分析,本文的研究工作主要围绕以下议题展开：1.研究反映应用特点的实用安全模型和安全性定义方法；2.研究实用安全协议的设计和分析方法；3.研究对已有安全应用协议的改进方法；4.研究新的安全应用问题和设计相关的安全应用协议；与之对应,本文在研究过程中取得的主要研究成果包括：1.在实用安全模型研究方面探讨了实用安全模型的构建方法,提出了一个以近似安全计算理论为基础的应用的安全模型和安全性定义,并以之作为在不满足一般性安全条件的应用环境下,进行安全协议设计和安全性分析的理论基础；2.在实用安全协议设计方法方面通过吸取安全协议通用设计方法的研究成果,提出了利用秘密规约和合成定理的安全协议设计方法,为应用安全协议设计提供了一种有效的方法。3.在对已有安全应有协议的改进方面重点研究了在电子商务应用领域具有重要实用价值的公平交换协议,提出了对两个重要的公平交换协议的改进方案。针对无中心分布式网络应用环境,提出了一个无第三方公平交换的实现框架,为公平交换应用领域的推广做出了一定的贡献。4.在新安全应用问题研究和相关安全协议设计方面针对电子商务中的安全价格协商问题和分层传感器网络中的安全数据采集问题,分别提出了两个基于安全多方计算技术的应用协议,对于探索安全多方计算的新应用领域做出了有益的尝试。更多还原

【Abstract】 Secure multi-party computation is one of the most important areas in modern cryptography. For secure multi-party computation in distributed networks, it is essential to realize multi-party participation of secure cooperative computation. As most of the current secure protocols in network applications can be considered as certain secure multi-party computation protocols, the secure multi-party computation has attracted attention of many researchers.Current research on secure multi-party computation mainly concentrates on two aspects. One is on the fundamental theoretical research, including research on the secure model and the definition of general security, on basic protocols and general design methods of secure multi-party computation, and on analytical methods for protocol security. The major achievements include the vigorous definition of security using the semi-trust model and the malicious model, feasibility of secure protocols under various secure models, and the general design methods for secure protocols. The other aspect is on the practical application of secure protocols, including electronic auction, electronic voting, fair exchange, privacy preserving data mining, etc. As a result, large amount of secure protocols have been proposed.Besides the above mentioned accomplishments in the theoretical and practical study on secure multi-party computation, there are still many important research questions remaining to be answered. In the theoretical aspect, current secure model and definition of general security cannot reflect characteristics of different applications. A more practical secure model is needed to be investigated. Protocol design using general design methods is normally inefficient. The protocol design methods specific to certain applications are worth further investigation. In the design of practical secure protocols, current secure protocols can be improved. To deal with new problems abstracted from applications, new secure protocols need to be designed.Based on the above discussions, this thesis covers the following topics:1. Investigate practical secure model and definition of general security that consider application characteristics. 2. Investigate practical design and analysis methods for secure protocols.3. Investigate methods that improve existing secure protocols.4. Investigate new secure applications and corresponding secure protocol design.Accordingly, this dissertation has the following accomplishments:1. Regarding the practical secure model The construction of practical secure model is investigated. As a result, an application oriented secure model and definition of security is proposed which is based on the theory of secure computation of approximations, and used as the theoretical foundation to design secure protocols and analyze security.2. Regarding the design methods of practical secure protocols A design method is proposed by using private reduction and composition theorem. This method provides an efficient way to design practical secure protocols.3. Regarding improving existing secure protocols The research works is focused on fair exchange, which is considered to be important in e-commerce. Two optimized fair exchange protocols are proposed that improve the performace of original versions. In particularly, a realistic structure is proposed for non-third party fair exchange in distributed networks, which contributes to the popularization of fair exchange in various applications.4. Regarding new secure applications and corresponding security protocol design Two secure multi-party computation based protocols are proposed for price negotiation in e-commerce and tiered wireless sensor networks, respectively. This is a valuable endeavor to explore new areas using secure multi-party computation.更多还原