LBCSC: Lattice‐based chameleon signcryption scheme for secure and privacy‐preserving vehicular communications

Abstract Guaranteeing the anonymity of the vehicle and the integrity of the transmitted message are two indispensable conditions in vehicular ad‐hoc network. Anonymous signature can achieve the two function. However, existing anonymous signature schemes constructed based on traditional cryptosystems cannot withstand quantum attacks. In addition, in some cases, the schemes need to satisfy the non‐transferability of signatures to solve the problem of signature misuse due to publicly verified signatures. In order to resist quantum attacks and address the problem of signature misuse, this article proposes a lattice‐based chameleon signcryption scheme, which aims to protect vehicle identity and data security. The scheme is resistant to quantum attacks and satisfies signature non‐transferability, signer rejectability and non‐repudiation. Especially, we prove that the proposed scheme is secure in the Standard Model based on the error learning problem and the classical lattice small integer solution problem.