An Improved Privacy-Aware Handoff Authentication Protocol for VANETs

Vehicles handover from one road-side unit to another is a common phenomenon in vehicular ad-hoc networks (VANETs). Authenticating vehicles effectively is the key to success of VANETs. Li and Liu et al. proposed a lightweight identity authentication protocol (LIAP) for VANTEs recently, which is based on the concept of dynamic session secret process instead of conventional cryptographic schemes. LIAP possesses many advantages of againsting major existing attacks and performing well at efficiency and low consumption. However, we have demonstrated that the protocol LIAP doesn't provide user location privacy protection and the resistance of parallel session attack is weak. Therefore, to enhance security of the protocol LIAP, we concatenate the terminal's pseudo-identity with a random number, then encrypt the connected information by using quadratic residues operation, the generated dynamic identity can against the user location tracking attack. Furthermore, in order to against the parallel session attack during the handover procedure, a new road side unit regenerated a new session secret sequence and computed a challenge sequence with the terminal user's pseudo-identity through XOR encryption. Through security analysis and experiments, our scheme has higher efficiency and better performance to be applicable to VANETS compared with other existing schemes.