Enhanced privacy and reliability for secure geocasting in VANET

Current geocasting algorithms for VANETs are being designed to enable either private or reliable communications, but not both. Existing algorithms preserve privacy by minimizing the information used for routing, and sacrifice message delivery success. On the other hand, reliable protocols often store node information that can be used to compromise a vehicle´s privacy. We propose a secure, privacy-preserving geocasting protocol for VANETs that uses direction-based dissemination and ensures confidentiality. Privacy is achieved via unlinkable pseudonymous channels, and encryption and authentication with a public key technique. To reduce message duplication, we apply dynamic traffic restriction and probabilistic forwarding techniques, which depend on message rate and cumulative payload, as well as the value of the angle of spreading of the direction-based scheme. Our analysis shows that due to dynamic traffic restriction, node density does not meaningfully affect reliability, while the angle of spreading does have a significant influence.