Joint Privacy and Reputation Assurance for VANETs

Privacy protection and reputation management, both indispensible to Vehicular Ad Hoc Networks (VANETs), impose conflicting requirements: privacy protection makes it challenging to maintain the reputation history of any node; reputation management requires real-time reputation manifestation at risk of easier vehicle tracking. Here, a novel Joint Privacy and Reputation Assurance (JPRA) scheme is proposed to solve these conflicting requirements. To make reputation aggregation secure and efficient in face of high node mobility and privacy protection, JPRA adopts a localized reputation management approach. A reputation relay procedure ensures that the complete reputation information of any node is always maintained by itself and its 1-hop neighbors in face of network topology changes. Neighbor-assisted reputation update, with partially blind signature, allows each node to securely update its reputation without harming its privacy in JPRA. Eventually, to make reputation manifestation privacy-preserving, a conditional reputation discretization algorithm is proposed to allow the honest nodes to manifest a common reputation value. Analysis and simulations show that JPRA efficiently and synergistically supports the coexistence of reputation schemes and privacy schemes in VANETs.