Date Added: Sep 2009
This paper introduces an efficient and spontaneous privacy-preserving protocol for vehicular ad-hoc networks based on revocable ring signature. The proposed protocol has three appealing characteristics: First, it offers conditional privacy-preservation: While a receiver can verify that a message issuer is an authorized participant in the system only a trusted authority can reveal the true identity of a message sender. Second, it is spontaneous: Safety messages can be authenticated locally, without support from the roadside units or contacting other vehicles. Third, it is efficient by offering fast message authentication and verification, cost-effective identity tracking in case of a dispute, and low storage requirements.