车载网中可证安全的无证书聚合签名算法

为了实现车载自组织网络中车辆节点之间信息传输的安全认证，该文设计了一种无证书聚合签名方案。提出的方案采用无证书密码体制，消除了复杂的证书维护成本，同时也解决了密钥托管问题。通过路侧单元生成的假名与周围节点进行通信，实现了车辆用户的条件隐私保护。在随机预言模型下，证明了方案满足自适应选择消息攻击下的存在性不可伪造。然后，分析了方案的实现效率，并模拟实现了车载自组网(VANET)环境中车流密度与消息验证的时间延迟之间的关系。结果表明，该方案满足消息的认证性、匿名性、不可伪造性和可追踪性等性质，并且通信效率高、消息验证的时延短，更适合于动态的车载自组织网络环境。

Probably Secure Cetificateless Aggregate Signature Algorithm for Vehicular Ad hoc Network

In order to realize the security authentication of the information transmission between vehicle nodes in vehicular Ad hoc networks, a certificateless aggregate signature scheme is designed. The proposed scheme uses certificateless cryptography, which eliminates the complex maintenance cost of certificate and solves the problem of key escrow. Communicating through pseudonyms and nodes around the roadside units generated, the conditional privacy protection is achieved for vehicle users. In the random oracle model, the scheme is proved to be existentially unforgeable against adaptive chosen message attack. Then, the efficiency of the scheme is analyzed, and the relationship between the traffic density in Vehicular Ad hoc NETwork (VANETs) environment and the time delay of message verification is simulated. The results show that the scheme satisfies the message authentication, anonymity, unforgeability and traceability, as well as the higher communication efficiency and the shorter delay of message verification, which is more suitable for dynamic vehicular Ad hoc network environment.