Generally, Vehicular Ad Hoc Networks (VANETs) make use of the Public Key Infrastructure (PKI) to authenticate and determine the integrity of traffic-related messages. One major issue faced by most current state of the art schemes that concentrate on secure communication in VANETs is that of efficiency. These schemes do possess the aforementioned properties of being able to authenticate messages as well as ensure their integrity. They however, in one way or the other fail to do so efficiently. Current schemes do not allow a Road-Side Unit (RSU) to efficiently authenticate a large number of messages generated from multiple vehicles in its communication range. This is due to the large computational overhead involved in doing so sequentially. In this paper, we propose an efficient Identity-based Conditional Privacy-Preserving Authentication (ID-CPPA) signature scheme based on bilinear map for Vehicle-To-Infrastructure (V2I) communication. This scheme uses general one-way hash functions rather than map-to-point hash functions. This increases the efficiency with which the signing as well as the verification of a message at the RSU is performed. In addition to this, our ID-CPPA signature scheme supports the batch signature verification method, which reduces the computational overhead on the RSU thereby allowing it to authenticate a large number of traffic-related messages from multiple vehicles in areas with high traffic density. The proposed scheme ensures security, i.e., unforgeability against the adaptive chosen-message attack and adaptive chosen-identity attack under the Inverse Computational Diffie-Hellman (Inv-CDH) problem in the Random Oracle Model (ROM). We show that this scheme is more efficient with respect to the computational cost it incurs as compared to similar schemes.

通常，车载自组织网络（VANET）利用公钥基础结构（PKI）来认证和确定与流量相关的消息的完整性。当前大多数专注于VANET中安全通信的现有技术方案所面临的一个主要问题是效率问题。这些方案确实具有能够验证消息并确保其完整性的上述属性。但是，它们不能以一种或另一种方式有效地做到这一点。当前方案不允许路边单元（RSU）有效地验证在其通信范围内从多辆车生成的大量消息。这是由于依次进行所涉及的大量计算开销。在本文中，我们提出了一种基于双线性映射的有效的基于身份的条件隐私保护身份验证（ID-CPPA）签名方案，用于车辆到基础设施（V2I）通信。此方案使用常规的单向哈希函数，而不是映射点哈希函数。这提高了在RSU上执行签名和消息验证的效率。除此之外，我们的ID-CPPA签名方案支持批量签名验证方法，这减少了RSU的计算开销，从而使它能够从交通密度高的地区的多辆汽车中认证大量与交通有关的消息。提议的方案确保安全性，即随机Oracle模型（ROM）中的Inv -CDH）问题。我们表明，与类似方案相比，该方案在产生的计算成本方面更为有效。