A novel construction of SDVS with secure disavowability

摘要

Designated verifier signature (DVS) and strong designated verifier signature (SDVS) exhibit perfect nontransferability, but does not provide secure disavowability or non-repudiation, which makes them more like a message authentication code rather than a digital signature. In these kinds of cryptographic primitives, the signer has to bear the responsibility of some "forged" signatures produced by the designated verifier. Therefore, it's highly essential to construct a strong designated verifier signature scheme with secure disavowability. In this paper, we resolve this problem by proposing a novel construction of a strong designated verifier signature with secure disavowability. The new scheme makes use of a chameleon hash function and supports the signer to have a complete control of his signature. The proposed scheme achieves unforgeability, nontransferability and secure disavowability. Compared with the previous constructions, the new proposal achieves higher computational efficiency and shorter signature length.