Secure VANET applications with a refined group signature

This paper proposes an application-friendly group signature (GS) model for wireless ad hoc network like Wireless Sensor Networks (WSN) or Vehicle ad hoc Network (VANET). Our new GS properties can be used to carry out potential solution to some real life problems. We modify Boneh, Boyen and Shacham (BBS) short GS to meet a restricted, but arguably sufficient set of privacy properties. In particular, we aggregate linking, direct opening, message-dependent opening (MDO), revoking, batch-verification in a single short GS scheme. Our link manager can link messages whether they are coming from the same messages or not without colluding to the opener. It helps relaxing strong privacy properties of GS to a lightly lesser one that fit certain application requirement. We introduce a new application to the ad hoc network security, that is, value-added service provider (VSP) with the help of MDO properties and redesign the traditional GS-friendly VANET architecture. Our revocation algorithm adapts both rekeying and verifier-local revocation (VLR) approaches to revoke illegitimate signers in a constant time. Finally, we present an optional batch verification system to expedite signature verification. Note that all these properties have already been shown in the literature scatteredly. The novelty of our proposal stems from accumulating all these properties in a single GS scheme that can best fit to the application demand.