Security and privacy in vehicular ad hoc networks (VANETs) are challenging in terms of Intelligent Transportation Systems (ITS) features. The distribution and decentralisation of vehicles could threaten location privacy and confidentiality in the absence of trusted third parties (TTP)s or if they are otherwise compromised. If the same digital signatures (or the same certificates) are used for different communications, then adversaries could easily apply linking attacks. Unfortunately, most of the existing schemes for VANETs in the literature do not satisfy the required levels of security, location privacy, and efficiency simultaneously. This paper presents a new and efficient end-to-end anonymous key exchange protocol based on Yang et al. 's self-blindable signatures. In our protocol, vehicles first privately blind their own private certificates for each communication outside the mix-zone and then compute an anonymous shared key based on zero-knowledge proof of knowledge (PoK). The efficiency comes from the fact that once the signatures are verified, the ephemeral values in PoK are also used to compute a shared key through an authenticated Diffie-Hellman key exchange protocol. Therefore, the protocol does not require any further external information to generate a shared key. Our protocol also does not require an interference with the Roadside Units or Certificate Authorities, and hence can be securely run outside the mixed-zones. We demonstrate the security of our protocol in an ideal/real simulation paradigm. Hence, our protocol achieves secure authentication, forward unlinkability, and accountability. Furthermore, the performance analysis shows that our protocol is more efficient in terms of computational and communication overheads compared to existing schemes.

车载自组织网络 (VANET) 的安全性和隐私性在智能交通系统 (ITS) 功能方面具有挑战性。在没有受信任的第三方 (TTP) 或以其他方式受到损害的情况下，车辆的分布和分散可能会威胁到位置隐私和机密性。如果相同的数字签名（或相同的证书）用于不同的通信，那么攻击者可以很容易地应用链接攻击。不幸的是，文献中大多数现有的 VANET 方案不能同时满足所需的安全性、位置隐私和效率水平。本文提出了一种基于 Yang等人的新型高效的端到端匿名密钥交换协议。的自盲签名。在我们的协议中，车辆首先为混合区外的每次通信私下隐藏自己的私有证书，然后基于零知识证明 ( PoK ) 计算匿名共享密钥。效率来自这样一个事实：一旦签名被验证，PoK中的临时值还用于通过经过身份验证的 Diffie-Hellman 密钥交换协议计算共享密钥。因此，该协议不需要任何进一步的外部信息来生成共享密钥。我们的协议也不需要干扰路边单元或证书颁发机构，因此可以在混合区之外安全地运行。我们在理想/真实的模拟范例中展示了我们协议的安全性。因此，我们的协议实现了安全认证、前向不可链接性和问责制。此外，性能分析表明，与现有方案相比，我们的协议在计算和通信开销方面更有效。