【作者】 阎军智；

【导师】 马建峰；

【作者基本信息】 西安电子科技大学 ， 密码学， 2009， 博士

【摘要】 随着数字通信技术、计算机技术和信息技术的迅速发展,群组通信被广泛应用于多种网络业务,以有效实现一对多、多对多的信息交换。为了保障群组通信的安全,通常在群组成员之间使用群组密钥加密通信信息,同时群组成员的动态变化要求对群组密钥进行安全有效的更新。在安全群组通信中,密钥管理机制的优劣直接关系到传输的安全性、稳定性和可靠性,对群组密钥管理机制的研究具有重要意义。本文研究了安全群组通信中的分层密钥管理技术,主要包括以下内容:1.提出了一种基于Diffe-Hellman算法的分层密钥分配方案,该方案分为系统建立、成员变化、拓扑变化等三个部分,能够支持成员以及分层拓扑结构的动态变化,具有实现简单、易于扩展等特点,可用于解决基于内容的分层访问控制问题。2.研究了分层访问控制中的密钥层次结构,将该结构归纳为三类,即基于用户的、基于资源的以及混合型密钥结构,同时研究了这些结构之间的相互关系,并将提出的密钥结构与现有的分层密钥分配模型相结合,分析了现有分层密钥分配模型在这些密钥结构中的性能。3.设计了一种适用于无线传感器网络中节点撤销的分层密钥预分配方案。该方案利用逻辑密钥树,采用一种分层的密钥分配方法实现节点的撤销,具体分为系统建立、对偶密钥协商、成员撤销和成员加入等部分。分析表明,该方案具有较小的存储、通信和计算开销。4.在通信质量较差的无线网络中,不能保证群组中每个成员都能正确地接收到每次群组密钥更新时的数据包,因此设计了一种无状态的分层密钥预分配方案。该方案以逻辑密钥树的形式对密钥进行组织管理,利用最大子树的共享密钥撤销被捕获的成员节点。最后,分别利用Akl-Taylor算法和基于Diffe-Hellman算法的分层密钥分配方法对本方案进行了改进。更多还原

【Abstract】 The development of digital communication, computer and information technolo-gies have made group communications widely applied into various kinds of networkservices to achieve effective one-to-many and many-to-many information exchanges.The general method to secure the group communication is encrypting the commu-nication messages by a group key shared among all the group members. The groupkey should be updated securely and effciently during the group member dynamics.In secure group communications, the key management mechanism determines thesecurity, stability and reliability of the communication, and thus, the study of groupkey management mechanism is of significance. The main contributions of this thesisare as follows:1. A hierarchical key assignment scheme based on Diffe-Hellman algorithm isproposed, which consists of the phases of system initialization and key updating,and supports user dynamics and topology changes. This scheme is ffexible and easyto deploy. It can be used for content access control.2. The key hierarchies in hierarchical access control systems are studied, andthey are divided into user-based, resource-based and unified key hierarchies. Therelationships among these different kinds of hierarchies are studied. The existinghierarchical key assignment models are combined with these hierarchies, and theireffciency is evaluated.3. An hierarchical key pre-distribution scheme which aims to revoke the com-promised sensor nodes in wireless sensor networks is proposed. This scheme is basedon a novel application of an a-ary logical key tree, and it consists of the phases of sys-tem initialization, pairwise key establishment, node revocation and addition. Theperformance analysis shows this scheme could provide suffcient secrecy with lowstorage, communication and computational overheads.4. In wireless networks with poor communication conditions, it cannot beguaranteed that every user could receive all the rekey packages. A logical key treebased and stateless hierarchical key pre-distribution scheme is proposed, which usesthe shared key of a maximum subtree to revoke the promised nodes. At last, theproposed scheme is improved by using Akl-Taylor and Hiffe-Hellman hierarchicalkey assignment algorithms respectively.更多还原