Vehicular ad hoc network(VANET) is the application of mobile ad hoc networks (MANETs) on the road of traffic. It is an important issue to achieve secure sharing of information among vehicles. Authenticated key agreement (AKA) is a good option to solve the problem. The security proofs of all known identity based two-party authenticated key agreement (IB2PAKA) schemes are given in the random oracle model(ROM). A cryptographic scheme, that is proven to be secure in ROM, is not necessarily safe in real life. Recently, Dang et al. presented an IB2PAKA scheme for VANET and claimed that it is provably secure in the extended Canetti-Krawczyk (eCK) model and ROM. In this paper, we indicate that Dang et al.’s scheme is not secure by showing two concrete attacks, then put forward a new IB2PAKA scheme and provide the security proofs in eCK model and the standard model (SM). Our scheme is suitable for VANET due to it does not require pairing operations and requires only four scale multiplication operations.

车载自组网（VANET）是移动自组网（MANET）在交通道路上的应用。实现车辆间信息的安全共享是一个重要的问题。身份验证密钥协议 (AKA) 是解决该问题的不错选择。在随机预言机模型（ROM）中给出了所有已知的基于身份的两方认证密钥协议（IB2PAKA）方案的安全证明。在 ROM 中被证明是安全的加密方案在现实生活中不一定是安全的。最近，当等人。提出了 VANET 的 IB2PAKA 方案，并声称它在扩展的 Canetti-Krawczyk (eCK) 模型和 ROM 中可证明是安全的。在本文中，我们通过展示两个具体的攻击来表明 Dang 等人的方案不安全，然后提出了一种新的IB2PAKA方案，并在eCK模型和标准模型（SM）中提供了安全证明。我们的方案适用于 VANET，因为它不需要配对操作，只需要四个尺度乘法操作。