Improved Access Control Mechanism in Vehicular Ad Hoc Networks

Access control of message is required when certain selected vehicles are granted access to information, instead of all vehicles within communication range. In these situations an access policy (consisting of attributes as road situation and vehicle type) is built into the vehicle and messages are encrypted using these access policies. Only valid vehicles possessing these attributes are able to decrypt the message. Huang and Verma [16] had proposed such an access control framework. The scheme assumed that the road-side units (RSU) are not compromised and had a very restricted access structure. We propose a new access control structure which eliminates the drawbacks of their schemes, by providing access control in presence of compromised RSU. Our technique permits a more general boolean access structure. Communication is possible between two vehicles which are monitored by two RSU, which was not permitted in [16]. The costs are comparable to that of [16].