PKI-SC: Public key infrastructure using symmetric key cryptography for authentication in VANETs

Main use of VANETs is to provide safety by exchanging the warning messages between the vehicles so, it is time constraint. There is also requirement to resist various abuses and security attacks. An ECDSA algorithm used with PKI system to provide security but, it comes with the authentication overhead. TESLA uses MAC algorithm but, it is not feasible for delay-intolerant VANETs. Here PKI-SC system is proposed in that MAC algorithm can be used with classical PKI system using certificate scheme. To make comparison between PKI and PKI-SC system, ECDSA and MAC algorithms respectively are implemented on nodes and, to compare communication delay packet size of both system is used. For the analysis purpose formulas and processing time has been used to see, how different parameters effects on the authentication delay hence, on the braking distance of the vehicles. Results conclude that authentication time is very low for proposed system, which is near to the message without security so, it will solve issue of availability and braking distance is very low for proposed system. So, using the proposed system provides security, communication delay is also reduced and there is no issue of authentication overhead. It also provides multi-hop communication that is not possible in TESLA.