Computationally Efficient Secure Access Control for Vehicular Ad Hoc Networks

In this paper, we design an access control mechanism for vehicular ad hoc network environment to enable only authorized vehicles to access data using attribute based encryption. The existing access control schemes are expensive in the sense that the ciphertext-length grows linearly with the number of attributes occurring in the access policy and the number of pairings needed for decryption is linear to the minimum number of attributes satisfying the access policy to decrypt a message. The main emphasis of our proposed construction is that it uses a constant number of pairings during encryption and decryption, while having a significant improvement in the communication overhead as compared to the existing schemes. We provide a concrete security analysis of our scheme in the generic group model. On a more positive note, our scheme resists collusion attacks made between any number of vehicles.