Non line of Sight Location Verification in EMAP for Vehicular Ad Hoc Networks

The security in VANETs is improvised with the involvement of Public Key Infrastructure (PKI) and Certificate Revocation List (CRL) through message authentication and the data transmissions are improved through NLOS. The direct communications between vehicles are blocked with interference of obstacles like trucks, buildings. These problems are overcome through NLOS conditions such as location verification and misbehavior detection. The neighborhood vehicles are tracked and are authenticated with EMAP. In EMAP, Certificates and signature matches with the CRL are used in checking and verifying the authenticity of any PKI system. Time consumption in checking the CRL is relatively less in EMAP because hash tables are used for searching process. Keys shared with the nonrevoked On-Board Units (OBUs) are used in Hashed Message Authentication Code (HMAC) for revocation checking process. End to end delay and message loss ratio is reduced here and thus the security and efficiency of VANETs are enhanced in EMAP. In EMAP,CRL checking process is improved by an efficient revocation checking process using a fast and secure HMAC function. EMAP is suitable not only for VANETs but also for any network employing a PKI system and also reduces the authentication delay.