Privacy protection and message authentication issues in VANETs have received great attention in academia. Many authentication schemes in VANETs have been proposed, but most of them are based on classical difficult problems such as factorization in RSA setting or Elliptic Curve setting and are therefore not quantum resistant. If a quantum computer becomes available in the next few decades, the security of these schemes will be at stake. This paper presents a vehicular lattice-based direct anonymous attestation (V-LDAA) scheme adopting an optimized signature scheme based on automorphism stability which achieves postquantum security. A distributed pseudonym update and vehicle revocation mechanism based on the lattice is introduced in this paper, which means vehicles can update their pseudonyms and revoke the identity certificate by themselves without the need for pseudonym resolutions or CRLs checking. Compared with the existing lattice-based attestation schemes in VANETs, computation costs during signing and verification operations in V-LDAA are no longer related to the number of users, which makes it suitable for large-scale VANETs. Security analysis shows that V-LDAA resists TPM theft attacks and provides users with user-controlled anonymity, user-controlled unlinkability, and unforgeability against quantum adversaries. Experimental results show that V-LDAA reduces the blind signature size by 18%. The speed of blind signing is increased by 30%, and blind verification operation is accelerated 3 times compared with the existing lattice-based direct anonymous attestation (LDAA) scheme.

中文翻译：

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V-LDAA：一种新的基于格子的 VANETs 系统直接匿名认证方案

VANETs中的隐私保护和消息认证问题在学术界备受关注。VANETs 中已经提出了许多认证方案，但大多数都是基于经典难题，例如 RSA 设置中的分解或椭圆曲线设置，因此不具有量子抗性。如果量子计算机在未来几十年内面世，这些方案的安全性将受到威胁。本文提出了一种基于车辆格的直接匿名证明（V-LDAA）方案，采用基于自同构稳定性的优化签名方案，实现后量子安全。本文介绍了一种基于格的分布式假名更新和车辆撤销机制，这意味着车辆可以自行更新假名和撤销身份证明，而无需假名解析或 CRL 检查。与VANETs中现有的基于格的证明方案相比，V-LDAA中签名和验证操作的计算成本不再与用户数量相关，这使其适用于大规模VANETs。安全分析表明，V-LDAA 抵抗 TPM 盗窃攻击，并为用户提供用户控制的匿名性、用户控制的不可链接性和对抗量子对手的不可伪造性。实验结果表明，V-LDAA 将盲签名大小减少了 18%。盲签速度提高30%，盲验证操作比现有的基于格的直接匿名认证（LDAA）方案加速3倍。