中文摘要：

由于不需要基础设施和复杂的安全引导过程，证书链成为移动自组织网络公钥管理的一种重要可选方案．现有方案很大程度上依赖于节点的移动性，具有很长的预热期，认证成功率低．通过实验分析表明：对大规模移动自组织网络进行分簇，在随机选取的两个簇首之间以一定的概率相互签发少量的证书，形成的证书图涌现出明显的小世界现象．在此基础上，提出了一种改进的自组织公钥管理方案，利用证书图的小世界特征改进本地证书库的创建和认证过程．仿真结果表明，提出的改进方案在相同环境下认证成功率达到80％以上，比原有方案约50％的认证成功率有很大的提高．

英文摘要：

Requiring no heavy infrastructure and complex bootstrapping, certificate chaining becomes a potential candidate for self-organized public key management for mobile ad hoc networks. The existing schemes rely on the mobility of nodes and need a long warm-up period. In this paper, analysis and experiment show that by signing a few certificates among cluster heads with certain probability in a large scale clustering network, certificate graph emerges apparent small world phenomenon. Based on the observation, an improved self-organized public key management scheme is proposed, which using small world phenomenon to improve the construction of local certificate repository and process of authentication. Simulation results show that the authentication success rate of proposed scheme is above 80 %, which is more effective than the rate of 50 % in the previous scheme.