Title: Provably secure fail-stop signature schemes based on RSA

Authors: Willy Susilo, Yi Mu

Addresses: Centre for Information Security Research, School of Information Technology and Computer Science, University of Wollongong, Wollongong 2522, Australia. ' Centre for Information Security Research, School of Information Technology and Computer Science, University of Wollongong, Wollongong 2522, Australia

Abstract: The security of ordinary digital signature schemes relies on a computational assumption. Fail-stop signature (FSS) schemes provide security for a forger with unlimited computational power by enabling the sender to provide a proof of forgery if it occurs. An attractive construction of FSS scheme based on factorisation is the RSA-based FSS schemes published in IWSEC |99, which allows the signer to provide a non-trivial factor of the modulus in the case of forgery. In this paper, firstly we review some remarks on the RSA-based FSS schemes, including a recently proposed |attack| which is incorrect. We note that the proposed scheme is not provably secure. Then we incorporate Hensel lifting techniques to create a provably secure variant of the scheme. As a result, our scheme is provably secure and has an explicit proof of forgery by allowing the sender to reveal the non-trivial factor of the modulus in the case of forgery. Among the existing FSS schemes based on the factorisation, our scheme is the only scheme which provides an explicit proof of forgery together with a provable security. We provide a complete security proof of our scheme.

Keywords: digital signature; fail-stop signature scheme; forgery; factorisation; RSA; Hensel-lifting techniques; provable security; FSS.

DOI: 10.1504/IJWMC.2005.008055

International Journal of Wireless and Mobile Computing, 2005 Vol.1 No.1, pp.53 - 60

Available online: 10 Nov 2005 *

Full-text access for editors Access for subscribers Purchase this article Comment on this article