Efficient Blockchain-Based Group Key Distribution for Secure Authentication in VANETs

This letter proposes a group key distribution scheme using smart contract-based blockchain technology. The smart contract's functions allow for securely distributing the group session key, following the initial legitimacy detection using public key infrastructure-based authentication. For message authentication, we propose a lightweight symmetric key cryptography-based group signature method, supporting the security and privacy requirements of vehicular ad hoc networks (VANETs). Our discussion examined the scheme's robustness against typical adversarial attacks. To evaluate the gas costs associated with smart contracts functions, we implemented it on the Ethereum main network. Finally, comprehensive analyses of computation and communication costs demonstrate the scheme's effectiveness. © 2019 IEEE.