On the Security of a Certificateless Strong Designated Verifier Signature Scheme with Non-delegatability
Shan Shan · 2020
Strong designated verifier signature scheme is a cryptographic primitive that aims at only enables the designated verifier to check the correctness of the signature, while any third party can not verify whether this signature is valid or not. Recently, Chen et al. [27] proposed the first certificateless strong designated verifier signature scheme with non-delegatability. They showed that their scheme satisfies the basic properties of a designated verifier signature scheme and resists the two types of adversaries in certificateless cryptography. However, in this paper, we show that the security models defined in their paper cannot describe the actual behavior of adversaries correctly. Their scheme still has some security weaknesses. We redefine the security models and give an effective attack on Chen's scheme under the new models.