Recent advance in wireless communication technologies have revolutionized human’s lifestyles by providing the best ever convenient and flexible Internet services access. With the plummeting costs of electronic components and the ever willingness of the manufacturers to increase road safety and to differentiate themselves from their competitors, vehicles are becoming “computers on wheels”. Lately, both the vehicular manufacturers and the telecommunications industries have geared up to equip each vehicle with the best technology that allows the drivers and passengers from different vehicles to communicate with each other in order to improve the driving experience.
However, the integration of on board computers and positioning devices raise formidable research challenges. One of these challenges is security and so far very little attention has been dedicated to the security of vehicular networks. Yet, security is crucial and it must be considered along with the issue of privacy in VANETs. In addition, conditional privacy preservation must also be achieved in that the personal information of drivers and passengers should be protected. Hence, we take a step further to include backward unlinkability into Lin et al.’s GSIS scheme.

[1] KVH Industries, Inc. [Online]. Available: http://www.kvh.com/
[2] MSN TV. [Online]. Available: http://www.msntv.com/
[3] M. Raya and J. Hubaux, “The security of vehicular ad hoc networks,” in Proc. 3rd ACM Workshop on Security of Ad Hoc and Sensor Networks, Alexandria, VA, USA, November 2005.
[4] U.S. Department of Transportation, National highway traffic safety administration, Vehicle Safety Communications Project - Final Report. April 2006. [Online]. Available: http://www-nrd.nhtsa.dot.gov/pdf/nrd-12/060419-0843/PDFTOC.htm
[5] Traffic light. [Online] Available: http://en.wikipedia.org/wiki/Traffic light
[6] C. Liu and J. T. Yu, “An analysis of DoS attacks on wireless LAN,” in Proc. 6th IASTED International Multi-Conference on Wireless and Optical Communications, Banff, Alberta, Canada, July 2006.
[7] D. Chaum and E. van Heijst, “Group signatures,” in Proc. Advances in
Cryptology - Eurocrypt’91, ser. LNCS, vol. 576. Springer-Verlag, pp.
257-265, 1991.
[8] A. Shamir, “Identity-based cryptosystems and signature schemes,” in
Proc. Advances in Cryptology - Crypto’84, ser. LNCS, vol. 196.
Springer-Verlag, pp. 47-53, 1984.
[9] D. Boneh and M. Franklin, “Identity-based encryption from the Weil pairing,” in Proc. Advances in Cryptology - Crypto’01, ser. LNCS, vol. 2139. Springer-Verlag, pp. 213-229, 2001.
[10] X. Lin, X.Sun and P. Ho, GSIS: A Secure and Privacy Preserving Protocol for Vehicular Communications. http://www-ieeexplore.ieee.org/iel5/25/26830/101109TVT2007906878.pdf
[11] J. Tian and L. Coletti, “Routing Approach in cartalk 2000 project,” in Proc. 13th IST Mobile and Wireless Communications Summit, Aveiro, Portugal, June 2003.
[12] J. Luo and J.-P. Hubaux, “A survey of inter-vehicle communication,” Technical Report IC/2004/24, School of Computer and Communication Sciences. EPFL, Lausanne, Switzerland, 2004.
[13] V. Namboodiri, M. Agarwal, and L. Gao, “A study on the feasibility of mobile gateways for vehicular ad-hoc networks,” in Proc. 1st ACM International Workshop on Vehicular Ad Hoc Networks, Philadelphia, PA, USA, October 2004.
[14] T. Kosch, W. Franz, DaimlerChrysler. “Technical concept and prerequisites of car-to-car communication,” in Proc. 5th European Congress and Exhibition on Intelligent Transport Systems and Services, Hannover, Germany, June 2005.
[15] R. M. Yadumurthy, A. C. H., M. Sadashivaiah and R. Makanaboyina. “Reliable MAC broadcast protocol in directional and omni-directional transmissions for vehicular ad hoc networks,” in Proc. 2nd ACM International Workshop on Vehicular Ad Hoc Networks, Cologne, Germany, September 2005.
[16] P. Klaus, T. Nowey, C. Mletzko, “Towards a security architecture for vehicular ad hoc networks,” in Proc. 1st International Conference on Availability, Reliability and Security, Vienna, Austria, April 2006.
[17] A. Aijaz, B. Bochow, D. Florian, A. Festag, M. Gerlach, R. Kroh, and L. Tim, “Attacks on inter vehicle communication systems - an analysis,” in Proc. 3rd International Workshop on Intelligent Transportation, Hamburg, Germany, March 2006.
[18] G. Holland and T ElBatt. “Towards Characterizing and Classifying Communication-based Automotice Applications from a Wireless Networking Perspective”
[19] D. Boneh, X. Boyen, and Hovav Shacham. “Short group signatures,” in Proc. Advances in Cryptology - Crypto’04, ser. LNCS, vol. 3152. Springer-Verlag, pp. 41-55, 2004.
[20]Verifier-Local Revocation Group Signature Schemes with Backward Unlinkability from Bilinear Maps, IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences Vol.E90-A No.1 pp.65-74. T. Nakanishi and N. Funabiki. “Verifier-Local Revocation Group Signature Schemes with Backward Unlinkability from Bilinear Maps,”
[21]OSI Reference Model http://en.wikipedia.org/wiki 10 July 2008
[22] NHTSA, Vehicle Safety Communications Project Final Report, Appendix J: WAVE/DSRC Standards, http://www-nrd.nhtsa.dot.gov/pdf/nrd-12/060419-0843/PDFs/AppendixJ.pdf
[23] G. Atenies, D. Song and G. Tsudik, “Quasi-efficient revocation of group signatures,” in Proc. Financial Cryptography, Southampton, Bermuda, March 2002.
[24] D. Boneh, and H. Shacham, “Group signatures with verifier-local revocation,” in Proc. ACM CCS, Washington, DC, USA, October 2004.
[25] A. Kiayias, Y. Tsiounis, and M. Yung, “Traceable signature,” in Proc. Advances in Cryptology - Eurocrypt’04, ser. LNCS, vol. 3027. Springer- Verlag, pp. 571-589, 2004.