This report identifies the security approach associated with a communications data delivery system that supports vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. The report describes the risks associated with communications security and identifies approaches for addressing those risks. It also identifies and describes the policy and institutional issues that require focus in support of implementation and operations, as well as the balance needed among the priorities of security and safety with cost, privacy, enforcement, and other institutional issues.