TEMPLATE DESIGN © Privacy Issues of Vehicular Ad-hoc Networks (VANETs) Hang Dok and Ruben Echevarria Advisor: Dr. Huirong Fu Objectives Introduction Privacy Evaluation Conclusion The Vehicular Ad-Hoc Network, better known as VANET, is a network devoted to communication between vehicles and roadside units. With such technology, vehicle owners could increase safety and simplify their everyday drives. One of the safety increasing features includes warning messages of oncoming accident sites in real time. One of the simplifying features includes messages with traffic updates to warn about possible traffic congestions on a desired route. Privacy is an important aspect for VANET to be successful and accepted by the majority. Proposed Solution To measure the success of the solution proposed, privacy levels need to be measured by finding the anonymity set and entropy level. An anonymity set is the number of possibilities an attacker has to track the vehicle. In the proposed solution, the number of vehicles exiting the combination of zones is the anonymity set. Parameters Number of lanes for vehicle to exit (no U turns) Rate (number of vehicles per given time) for lane i Time (min and max times for vehicle to travel in silent period) Anonymity set to this solution is (SA) SA= Entropy is a measure of the uncertainty of tracking. In this case we are measuring the solution we proposed to see whether high anonymity set is probable. H= Given that the methods of the attacker are unknown, the probabilities for all the anonymity sets are all equal. First we assume that the only attack is listening to transmissions (messages being received and sent). We also assume that there are no surveillance cameras and everyone within the network is not a malicious attacker. Benefits Random busy road intersection consists of combination of Mix Zone, Silent Periods, and Group Navigation Legitimate network has a secret key present at vehicle registration Road Side Unit distribute encrypt group keys, pseudonyms and Mac address Forced to group navigate Groups travel in vehicular network to avoid location tracking Able to switch from group leader to no leader Attacks and Solutions Fig. 1 Group key 13, 12, 72, 41 enter Mix Zone Fig. 2 Group key 13 and 12 enter Silent Period Fig. 3 Group key 13 and 12 are assigned group key 55 Group key 72 and 41 enter Silent Period Fig. 4 Group key 72 and 41 are assigned group key 55 Tracking is very dangerous and attackers could use very little information to track a person using VANET. Example Attack 1: Interception of radio waves and linking pseudonyms By listening to radio transmission Steal identities, private keys, track routes, link pseudonyms Solution: Random Silent Periods-randomly chosen periods which vehicles are forced to remain silent Mix Zones-predetermined regions where vehicles are required to change pseudonyms and Mac address CMixes-extension of the mix zone, vehicles receive a symmetric key used to secure the messages Secure messages in region Dense regions and highest mixing Example Attack 2: Accessing Malware servers Manipulate and steal messages, track location, link pseudonyms Solution: Group navigation-a group traveling avg. velocity in general direction consist of group leader, group members, and a group key Able to communicate outside and inside of group Preserve group identity and reduce pseudonyms Along with our proposed solution to retaining privacy, VANET could be a more trusted and therefore accepted network for vehicle owners. With such technology, vehicle owners could increase safety and simplify their everyday drives. Acknowledgement Understand Privacy Issues of VANET Propose Solution for Location Privacy Protection This research work was conducted at Oakland University in the UnCoRe program - REU funded by the NSF under grant number Therefore, VANET must have a way to validate transmissions and keep security while retaining privacy, ruling out anonymity. Some researched ways to be able to help keep privacy are pseudonyms and keys. Pseudonyms-fictitious names given to vehicles to prevent tracking. Keys-types of pseudonyms that secure the communication between the sender and receiver Symmetric key-a key to encrypt and decrypt messages, only be seen by only certain individuals with some sort of mutual agreement Motor vehicle title/registration Private keys Time/Routine routes Full Name Identification card Bills In reality the network would fail if anonymity was introduced. False messages could be sent and cause traffic jams or accidents. Anonymity would not allow law enforcement to track vehicles.