Privacy Protection of VANET Based on Traceable Ring Signature on Ideal Lattice

With the development of the Vehicular Ad-Hoc Network (VANET), protecting user privacy while ensuring security has become an immense challenge. A ring signature has the characteristics of no manager and unconditional anonymity, which can substantially protect user privacy. However, two problems exist in practical applications: first, unconditional anonymity cannot track the signer, which has potential security risks; and second, ordinary ring signatures cannot resist quantum attacks. In response to these problems, this paper proposes a Traceable Ring Signature (TRS) scheme on ideal lattice. In the scheme, the traceability of the ring signature is achieved by adding information to the ring signature. Selecting the algorithm on the ideal lattice to generate the master key can effectively resist quantum attacks. The scheme gives a detailed security proof and efficiency analysis. The new scheme has strong unforgeability for the difficult problem of Short Integer Solution (SIS) Question and a smaller signature size.