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：

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LB-CLAS：用于 VANET 的基于 Lattice 的条件隐私保护无证书聚合签名方案


车载自组网 （VANET） 的快速发展为智能交通带来了极大的便利，VANET 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。针对在满足安全性和隐私性的条件下如何保证 VANET 中信息的安全传输问题，我们提出了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 方案没有使用数论研究单元 （NTRU） 晶格和离散高斯采样，而是基于代数晶格。此外，基于小整数解 （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 方案是自适应选择消息攻击 （EUF-CMA） 下的存在不可伪造性。我们的 LB-CLAS 方案在车对车 （V2V） 模式下采用个人签名验证，同时在车对基础设施 （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的高存储开销和计算成本问题。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 方案分别减少了超过 17.6% 和 43.4% 的签名和验证开销。我们的 LB-CLAS 程序在批量验证方面也具有显著优势。 随着车辆数量的增加，我们的批次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，其签名大小比相同安全级别下最高效的现有方案小 1 倍。