Secure Universal Designated Verifier Signature and its Variant for Privacy Protection
Based on the bilinear inverse Diffie-Hellman problem (BIDHP), we first propose a provably secure probabilistic signature scheme. Furthermore, we extend it into two universal designated verifier signature (UDVS) schemes under the same computational assumption. The first one is a conventional UDVS scheme for one designated verifier while the other is designed for cooperative multi-verifier. UDVS schemes aim at protecting the privacy of signature holders and have practical benefits to the applications, e. g., the certificate for medical records and income summary, etc. The comparison results demonstrate that the signature generation and designation of our scheme are both pairing-free, which could benefit the application of devices with constrained computation. We also give formal security proofs of unforgeability against existential forgery under adaptive chosen-message attacks (EF-CMA) in the random oracle model.
universal designated verifier signature bilinear inverse diffie-hellman problem probabilistic signature random oracle privacy-preserving