An Attack on Libert et al.'s ID-Based Undeniable Signature Scheme
Zichen Li, C.F. Chong, Lucas C. K. Hui, Siu‐Ming Yiu, K. P. Chow, Wai Wan Tsang, Hsiu‐Wen Chan, Kevin K. H. Pun · 2007
In 2004, Libert and Quisquater proposed an identity based undeniable signature scheme using pairings over elliptic curves. In this article, we show that the scheme is not secure. In particular, if a valid message-signature pair has been revealed, an adversary can forge the signer’s signature for any arbitrary message for which the signer has no way to deny it. More importantly, through this example, we illustrate that the bilinear property of pairings, although is useful for the design of cryptographic schemes, is also a source for security flaws. Keywords: Attack, bilinear pairings, ID-based cryptography, undeniable signature 1