1. Wenmao Liu Harbin Institute of Technology China

2. Outline ITS & VANETs Security Issues and Solutions An autonomous architecture Conclusion

3. Problems in current TS Congestions Accidents

4. ITS & VANETs Intelligent Transportation Systems(ITS) Systems adding information and communications technology to transport infrastructure and vehicles. Vehicular Ad-Hoc Networks(VANETs) Subset of MANETs Vehicles talk to each other and the road side infrastructures with wireless devices Intelligent ?

5. Benefits of VANETs Congestions : reduced Accidents : avoided

6. Benefit of VANETs Improve entertainment WIFI access Online music Real time position Find restaurants …

7. Security Issues Driving is a life-or-death matter Many attackers for many purposes Terrorists Crackers Message Blockers Illusion makers

8. Solutions Cryptography Intrusion Detection Authentication (PKI) Pseudonym (fake ID)

9. Scenario

10. An autonomous architecture

11. Servers CA clusters Log servers Application Servers Roadside infrastructures Vehicles

12. Autonomous system setup Node deployment Backbone node generation Autonomous gather

13. Vehicle authentication Authentication process of a vehicle o to a roadside infrastructure r. r broadcasts its certificate. o verifies rs certificate. o challenges r and sends its own certificate as piggyback to save time r verifies os identity, and then answers the challenge o checks whether the return message value equal the challenge message, if yes, r is legal, vice versa. Then o calculates the challenge n and sends it back. r verifies os validity by checking the response

14. Secure Communication Pseudonym scope Certificate Cache & Forward T cache = Length/ Speed n Length = (r 2 (d mn sin ) 2 + d mn cos α) 1/2

15. Conclusion ITS and VANETs offer promising future for transportation. Reducing overheads of roadside infrastructures A complete authentication Regional trust relationship and autonomy guarantee scalability

16. The End