Breaking Pomykala-Barabasz Threshold Proxy Signature Scheme

Article type: Research Article

Authors: Shao, Zuhua

Affiliations: Zhejiang University of Science and Technology, No. 318, LiuHe Road, Hangzhou Zhejiang, 310023, P. R. of China. [email protected]

Note: [] Address for correspondence: Zhejiang University of Science and Technology, No. 318, LiuHe Road, Hangzhou, Zhejiang, 310023, P. R. of China

Abstract: In 2006, Pomykala and Barabasz proposed an elliptic curve based threshold proxy signature scheme with known signers. They claimed that their scheme was relatively simple in construction, had the properties of unforgeability and non-repudiation, and admitted the proactive security. Later, Li and Hu pointed out that the scheme of Pomykala and Barabasz was insecure against the conspiracy attack. And then, they proposed an improved scheme. In this paper, we not only show that the threshold proxy signature scheme of Pomykala and Barabasz is universal forgeable, but also show that the improvement of Li and Hu suffers from the rogue key attack.

Keywords: elliptic curve cryptosystems, threshold proxy signature scheme, secret sharing, rogue key attack

DOI: 10.3233/FI-2010-354

Journal: Fundamenta Informaticae, vol. 104, no. 4, pp. 385-392, 2010