A forward-secure and efficient authentication protocol through lattice-based group signature in VANETs scenarios

Message authentication has been a research hotspot in current vehicular ad hoc networks (VANETs). Many researchers adopt group signatures based on number-theoretic assumptions to authenticate the vehicular users’ identities. Nevertheless, the classical group signature is vulnerable to quantum computing attacks and without considering the negative consequences of secret key disclosure. In this paper, to address these problems, we propose a novel group signature protocol for authentication in VANETs, which is based on lattice cryptography to achieve quantum-resistance and Bonsai-tree signature architecture to achieve forward security. Our scheme is proven secure in terms of traceability, anonymity, and forward-security under the Short Integer Solution (SIS) and Learning With Errors (LWE) hardness. Through comprehensive performance evaluation, we demonstrate that the storage overhead of our scheme is relatively diminutive and the computation cost of the sign and verify algorithms are efficient and practical compared with other existing schemes.