Public Key Infrastructure (PKI) using Symmetric Key Cryptography (SC) in VANETs

Vehicular Ad-Hoc Network (VANETs) provides the vehicle to vehicle (V2V) communication for the safety application. There are many security requirements in VANETs. ECDSA algorithm fulfils all the security requirements but it’s come with the processing overhead and there is a chance of computation based DoS attack. However the VANETs are the time constrained each safety message should be reached at a time to other vehicles. TESLA uses the symmetric key cryptography that is MAC algorithm but it is not that much scalable as compared to ECDSA because of multi-hop communication is not possible in TESLA and also it uses the delay key disclosure so till that the message and MAC has to be stored in the memory so there is chances of memory based DoS attack in TESLA. So if we use the MAC algorithm in the classical PKI system in place of ECDSA algorithm than it can reduce the processing overhead associated with ECDSA so time will be low for each message authentication and it also mitigate the problem of memory based and computation based DoS attacks that can be useful for the VANETs safety related applications as safety applications are time constraint. Keywords— OBU, TPM, PKI, Group Signature, ECDSA, TESLA, MAC.