The insecurity of a certificateless undeniable signature scheme
Rouzbeh Behnia, Swee‐Huay Heng · 2016
Duan proposed the first certificateless undeniable signature scheme in 2008. Later in 2012, Zhao and Ye proffered an efficient scheme which enjoys from a pairing-free sign algorithm. In this paper, we prove the insecurity of their efficient scheme by mounting two attacks on its invisibility and non-impersonation. In addition, we propose an improved scheme that addresses both of the above attacks while providing better flexibility and additional features for the signer.