Abstract:

Groupsignature based authentication is a promising approach for addressing the security and privacy issues in vehicular ad hoc networks(VANETs). However, it is prone to causing huge revocation overhead in VANETs with millions of nodes and serious security risks. To solve this problem, we develop a distributed key management scheme（DKM）where the whole domain of VANET is divided into several subregions, and any vehicle has to update its group secret key periodically from the regional group manager who manages the region where the vehicle stays. In this way, a revoked membership is just notified in a subregion but not the whole domain. Therefore, the average size of the revocation list in each subregion decreases. Moreover, the proposed key updating process which guarantees a vehicle can obtain an updated group secret key from a regional authority without leaking the value of the group secret key to the regional authority. Performance analysis demonstrates that DKM can reduce the revocation cost significantly while keeping the authentication overhead the same as the the original group signature algorithm.

Key words: vehicular ad hoc network;privacy preservation;group signature;distributed key management