Conditional Privacy-Preserving Authentication Protocol with Dynamic Membership Updating for VANETs

Existing conditional anonymous authentication protocols to secure the group communication in VANETs (Vehicular Ad hoc Networks) render challenges such as dynamically updating membership in a domain and achieving vehicle user's privacy preservation. This paper elegantly addresses these challenges by proposing a novel conditional privacy-preserving authentication with dynamic membership for VANETs depending on chinese remainder theorem (CRT). Specifically, the CRT is utilized by a trusted authority to securely disseminate a domain key for the authorized vehicles in the same domain, where each vehicle in this domain is able to obtain the domain key by only performing one modulo division operation in case of domain key updating. Distinct from the previous works in this field, our proposed protocol not only achieves message authentication, anonymity and conditional privacy-preserving, but also provides forward security and backward security of vehicles. Theoretical analysis and experiment simulation demonstrate that the proposed protocol is provably secure and highly feasible.