Hybrid and Hierarchical Aggregation-Verification Scheme for VANET

To deal with the security and privacy issues in vehicular ad hoc network (VANET), digital signature based on public key infrastructure (PKI) is recognized as being the most mature and popular approach. However, existing secure and privacy-preserving schemes for vehicular communications face some challenges, e.g., fast verification of signatures and certificates, reducing the storage/transmission overheads, avoiding the dependence on ideal tamper-proof devices. In this paper, we propose a hybrid and hierarchical aggregation-verification scheme for efficient verification of certificates and signatures on safety messages in VANET. In our scheme, short-term anonymous certificates and aggregate signatures are employed to guarantee the security and privacy of the VANET system. A novel hybrid aggregation-verification technique is proposed to firstly aggregate the signatures in different certificates and signatures on safety messages into fixed length aggregate signature and then verify the aggregate signature with very short delay. To the best of our knowledge, this paper achieves signature aggregation and verification of such kind for the first time. Further, our scheme also enables hierarchical aggregation-verification of certificates and signatures in VANET.