Secure and privacy-preserving, timed vehicular communications

We consider the problem of privacy (anonymity) and security in vehicular (V2V) communication, in particular securing routine safety messages. Traditional public key mechanisms are not appropriate for such applications because of the large number of safety messages that have to be transmitted by each vehicle, typically one message every 100−300ms. We first show that a recently proposed V2V communication scheme, the TSVC, based on the Time Efficient Stream Loss-tolerant Authentication (TESLA) scheme, is subject to an impersonation attack in which the adversary can distribute misleading safety information to vehicles, and propose a modification that secures it against such attacks. We then address general concerns regarding the inappropriateness of TESLA for vehicular applications (caused by the delayed authentication and buffer overflows), and propose a V2V communication scheme based on a variant of TESLA, TESLA, for which there is no delay and packets are self-authenticating. This is appropriate for applications in which vehicles are in close proximity. Finally we combine both schemes to get a hybrid communication scheme that addresses in a flexible way the mobility requirements of V2V communications.