A Privacy Conserves Pseudonym Acquisition Scheme in Vehicular Communication Systems

Vehicular communication systems rely on temporary anonymous identities, i.e., pseudonyms, to avoid the possibility of tracking vehicles. If a vehicle uses only one pseudonym, an adversary can easily follow the vehicle by observing and linking messages signed under that pseudonym. Therefore, the vehicles acquire a set of pseudonyms from the Pseudonym Certificate Authority. If a vehicle would be unable to obtain these pseudonyms because of the bad communication and delay in processing from the roadside unit, it would not utilize the communication system without compromising the privacy of location. Hence, security and privacy techniques proposed for conventional vehicular ad-hoc network's pseudonym-changing strategy may not scale well in such early deployed scenarios. This paper addresses the above-mentioned problem by offering a secure pseudonym scheme. Under this scheme, a vehicle can generate its pseudonyms using Gao Algorithm. Pseudonym Certificate Authority (PCA) issues one pseudonym for one vehicle that is sent to vehicles after encryption. The Gao Algorithm automatically generates sub-pseudonyms that are useable for 10 days. Consequently, the PCA requires less memory while providing maximum location confidentiality, and there is almost no complexity in managing pseudonyms. The Gao Algorithm uses encrypted identities so that only the central server knows the real identities of vehicles. We conduct simulations to verify the performance of the Gao Algorithm. Results show that the Gao Algorithm is expressively better than current strategies. Besides, even in the absence of roadside unit connections and low traffic on the road, the Gao Algorithm can achieve promising performance.