论文标题:无可信中心的（t，n）门限群签名方案研究
Study on (t,n) Threshold Group Signature Scheme without Trusted Party
论文作者
论文导师 任小康,论文学位 硕士,论文专业 计算机应用技术
论文单位 西北师范大学,点击次数 103,论文页数 52页File Size3055K
2007-05-01论文网 http://www.lw23.com/lunwen_834173382/
digital signature;;mobile Ad Hoc networks(MANET);;elliptic curve cryptosystem (ECC) ;; threshold group signature
本文研究的主要内容是基于椭圆曲线的无可信中心的(t,n)门限群签名方案及其在移动Ad Hoc网络中的应用。 本文在一种改进的椭圆曲线数字签名算法的基础上,采用Shamir门限秘密共享技术设计了一种新的基于椭圆曲线的无可信中心的(t,n)门限群签名方案。该新方案具有以下优点:采用无可信中心的秘密共享形式使得系统安全性得到提高,同时也弱化了应用门限签名方案的前提条件,扩大了其应用范围;与现有的门限签名方案相比,该方案无需可信中心管理签名者的密钥,也无需维护安全信道,因此,密钥管理简单,显著地减少了通信量和计算量,提高了系统效率,具有更好的适应性。文中还详细分析了对本方案各种可能的攻击方式,包括在门限签名方案中常见的、非常有效的伪造攻击、合谋攻击等。通过对方案的安全性分析,可知个体签名和群签名都是不可伪造的,并且在整个签名过程中都没有任何系统秘密信息的泄露。因此,该方案具有较强理论意义和较好的实际应用价值。 移动Ad Hoc网络是由一组带有无线通信收发装置的移动终端节点组成的一个多跳、临时、无可信中心的网络。由于移动Ad Hoc网络具有资源有限、拓扑动态、路由多跳、低带宽等特性,使得它面临的网络安全威胁比传统网络更为严峻。现在对其安全性的研究还处于起步阶段。由于移动Ad Hoc网络这些固有的特性使得传统网络中采用CA实现集中式证书服务的方法不再适用。为此,本文引入了身份证书机制,提出了一种新的基于椭圆曲线的适用于移动Ad Hoc网络的动态门限群签名方案。它将移动Ad Hoc网络的证书服务功能分布到整个网络中,任何大于门限数目的节点一起协作就可以为新加入的可信节点提供证书服务,从而实现了证书服务的本地化,并克服了其它分布式证书服务方案在系统初始化阶段需要可信第三方的限制。
This thesis focuses on (t,n) threshold group signature scheme without trusted party based on elliptic curve and its application in mobile Ad Hoc networks. Adopting Shamir threshold secret sharing technique, a new (t,n) threshold group signature scheme without trusted party based on an improved elliptic curve digital signature algorithm is proposed. This new scheme has following advantages: The system has no trusted authority which can enhance the system"s security and prevent from authority cheating, soften the precondition for threshold signature scheme and extend the extent of application of it; compared with existing control scheme, in the proposed scheme no trust center is needed for managing secret keys of signers, and no secure channel is maintained. So this scheme is easier in key management, significantly reduces the communication cost and computation cost, improve the system"s efficiency and provides better adaptability. The thesis analyzes some commonly used attacks in detail to verify its security, including the effectual attacks of forgery attack, collusion attack etc. Results of the security analysis showed that it was impossible for the adversary to forge the individual signature and group signature. There was no secret information leakage during the total signature process. So this scheme makes good sense both in theory and practice. Mobile Ad Hoc networks are composed of mobile terminal nodes with wireless communication devices typically characterized by their multi-hop, temporary and non-trusted-center. Mobile Ad Hoc networks have their unique characteristics, such as energy constrained, dynamic network topology, multiple hop routing, and limited bandwidth .These characteristics make mobile ad hoc networks facing more serious threats of network security than centralized wireless networks. Now research on security in MANET is still in its infancy. Because of the inherent characteristics in the Ad Hoc wireless network, the centralized authentication services provided by CA in traditional networks is not suitable for this network. In this paper an identity-certification mechanism is introduced and so a new dynamic threshold group signature scheme suitable for MANET based on elliptic curve is proposed. It distributes the authentication services into the whole network, so that each individual node can potentially provide other trusted nodes with certification services. The scheme not only localizes the authentication service but also adapts to the scalability. At the same time, this scheme overcomes the limit to other distributed certification services which need trusted party at initialization phase in the system.
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