The rapid development of vehicular ad-hoc networks (VANETs) has brought great convenience to intelligent transportation, and the secure transmission of information in VANETs has become a serious problem. In addition, the protection of private information of vehicles is also a key issue. Aiming at the problem of how to guarantee the secure transmission of information in VANETs under the condition of satisfying security and privacy, we propose a lattice-based conditional privacy-preserving certificateless aggregate signature scheme (LB-CLAS) for VANETs. Instead of using Number Theory Research Unit (NTRU) lattices and discrete Gaussian sampling, the proposed LB-CLAS scheme is based on algebraic lattice. In addition, based on the module version of Small Integer Solution (MSIS) and module version of Learning With Error (MLWE) hard problems, we prove that the LB-CLAS scheme is existential unforgeability under adaptively chosen message attacks (EUF-CMA). Our LB-CLAS scheme employs individual signature verification in vehicle-to-vehicle (V2V) mode, while utilizing aggregate signatures and batch verification in vehicle-to-infrastructure (V2I) mode, with slightly differing transmission parameters between the two modes. Based on Dilithium, our LB-CLAS scheme solves the problem of high storage overhead and computational cost of existing schemes. The performance analysis shows that our LB-CLAS scheme is more efficient in terms of computation cost, storage overhead, and power consumption compared to existing schemes. Compared with existing schemes, our LB-CLAS scheme reduces the signature and verification overheads by more than 17.6% and 43.4%, respectively. Our LB-CLAS program also has significant advantages in batch verification. As the number of vehicles increases, our batch certification time cost is reduced by more than 90%. In addition, our LB-CLAS scheme has the smallest signature length, with a signature size that is 1X smaller than the most efficient existing scheme for the same level of security.

中文翻译：

---

LB-CLAS：用于 VANET 的基于格的条件隐私保护无证书聚合签名方案


车载自组织网络（VANET）的快速发展给智能交通带来了极大的便利，而车载自组织网络中信息的安全传输已成为一个严重的问题。此外，车辆隐私信息的保护也是一个关键问题。针对如何在满足安全性和隐私性的情况下保证车载自组网中信息的安全传输问题，提出一种基于格的条件隐私保护无证书聚合签名方案（LB-CLAS）。所提出的 LB-CLAS 方案基于代数格，而不是使用数论研究单元 (NTRU) 格和离散高斯采样。此外，基于小整数解决方案（MSIS）的模块版本和错误学习（MLWE）难题的模块版本，我们证明了LB-CLAS方案在自适应选择消息攻击（EUF-CMA）下是存在不可伪造的。我们的LB-CLAS方案在车辆到车辆（V2V）模式下采用单独签名验证，而在车辆到基础设施（V2I）模式下采用聚合签名和批量验证，两种模式之间的传输参数略有不同。基于Dilithium，我们的LB-CLAS方案解决了现有方案存储开销和计算成本较高的问题。性能分析表明，与现有方案相比，我们的 LB-CLAS 方案在计算成本、存储开销和功耗方面更加高效。与现有方案相比，我们的LB-CLAS方案将签名和验证开销分别减少了17.6%和43.4%以上。我们的LB-CLAS方案在批量验证方面也具有显着优势。 随着车辆数量的增加，我们的批量认证时间成本降低了90%以上。此外，我们的LB-CLAS方案具有最小的签名长度，其签名大小比同等安全级别的最有效的现有方案小1倍。