A Survey of Existing Approaches for Secure Ad Hoc Routing and Their Applicability to VANETS

Vehicular ad hoc networks (VANETs) are the technical basis of an envisioned Intelligent transportation system. They offer a wide range of applications improving road safety and driving comfort. Since VANET applications affect safety-of-life, data security in a vehicular system is mandatory. The unique characteristics of VANETs compared to conventional mobile ad hoc networks and sensor networks pose particular challenges for a security solution for vehicular environment. For secure routing a number of approaches exist that have been designed for different environments and security objectives, mostly extending wellknown ad hoc routing protocols. This report systematically reviews the existing solutions and describes them on a comparable level of abstraction. Then, the report compares the solutions with respect to applied security mechanisms and performance criteria. Finally, it analyzes whether the features of the selected approaches meet VANETs requirements. From a high-level perspective the main security objectives (authentication, integrity, potentially non-repudiation) of the reviewed proposals fit well to the potential requirements of secure VANET routing. Since future VANET routing will likely be based on a specific routing protocol that utilizes positions of forwarding, additional security countermeasures are needed. These include mechanisms to ensure location privacy, to protect beaconing and location service as part of the routing protocol, and to prevent specific attacks that exploit the positions carried in data packets. These aspects necessitate the design of a unique security solution for VANETs. Nevertheless, it can also be concluded from analysis of the VANET characteristics that some aspects aid a security solution, such as less power and processing constraints, central registrations and periodic technical inspections, as well as existing law enforcement procedures. ! Also with Universidade de Aveiro, Instituto Telecomunicações, Portugal. 1 E. Fonseca and A. Festag acknowledge the support of the German Ministry of Education and Research (BMB+F) for the project ‘NoW – Network on Wheels’ under contract number 01AK064F. NEC Technical Report NLE-PR-2006-19, NEC Network Laboratories, March 2006, 28 pages.