车载自组网中可证明安全的无证书认证方案

认证协议的设计是目前车载自组网(VANET)安全领域的研究热点。现有的认证方案中普遍存在密钥托管带来的安全问题，以及使用计算量大的双线性对导致认证效率很低。针对以上问题，该文提出可证明安全的无证书批认证方案，方案中车辆的密钥由车辆自身和一个密钥生成中心共同生成，解决密钥需要托管给第三方维护的问题；方案的签名构造不使用计算量大的对运算，减少了计算开销；引入批认证来减少路边设施的认证负担，提高认证效率。基于求解椭圆曲线上的离散对数问题的困难性假设，在随机预言机模型中证明了该方案可以抵抗自适应选择消息和身份攻击，从而抵抗更改攻击和假冒攻击，并具有匿名性、可追踪性等特点。与现有方案相比，该方案实现了更高效的认证。

Provable Security Certificateless Authentication Scheme for Vehicular Ad hoc Network

The design of authentication protocol is a hot topic in the field of the security of Vehicular Ad hoc NETwork (VANET). There are security problems caused by key escrow in the existing authentication schemes. In order to solve this problem and achieve secure and efficient verification, an efficient pairing-free certificateless authentication  scheme with batch verification is proposed, in which the key of the vehicle is generated by the vehicle itself and a key generation center, which solves the problem that the key needs to be managed to the third party for maintenance. The bilinear pairing operation, one of the most complex operations in modern cryptography, is not used in the generation of vehicle’s signatures to reduce the computation cost of message verification. Unforgebility of the schemes against adaptively chosen-message and identity attack is proved under the difficulty of computing the discrete logarithm problem in the random oracle model to guarantee resistancy against modification and impersonation attacks, and has the characteristics of anonymity and traceability. Compared to the existing schemes, the proposed scheme is more efficient.