## Cryptology ePrint Archive: Report 2001/011

New Zero-knowledge Undeniable Signatures - Forgery of Signature Equivalent to Factorisation

Wenbo Mao

Abstract: We propose a new zero-knowledge undeniable signature scheme which is based on the intractability of computing high-order even powers modulo a composite. The new scheme has a number of desirable properties: (i) forgery of a signature (including existential forgery) is proven to be equivalent to factorisation, (ii) perfect zero-knowledge, (iii) efficient protocols for signature verification and non-signature denial: both measured by $O(\log k)$ (multiplications) where $1/k$ bounds the probability of error. For a denial protocol, this performance is unprecedented.

Category / Keywords: public-key cryptography / Undeniable signatures, Efficient zero-knowledge protocols

Publication Info: submitted

Date: received 15 Feb 2001, revised 15 Feb 2001, revised 19 Feb 2001, revised 28 Feb 2001, revised 28 Feb 2001

Contact author: wm at hplb hpl hp com

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Short URL: ia.cr/2001/011

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