Cryptology ePrint Archive: Report 2005/463

More short signatures without random oracles

Victor K. Wei and Tsz Hon Yuen

Abstract: We construct three new signatures and prove their securities without random oracles. They are motivated, respectively, by Boneh and Boyen's, Zhang, et al.'s, and Camenisch and Lysyanskaya's signatures without random oracles. The first two of our signatures are as short as Boneh and Boyen's (resp. Zhang, et al.'s} state-of-the-art short signatures. Our third signature is reducible to a modified LRSW Assumption but without their hypothesized external signing oracle. New and interesting variants of the q-SDH Assumption, the q-SR (Square Root) Assumption are also presented. New and independently interesting proof techniques extending the two-mode technique of Boneh and Boyen are used, including a combined three-mode simulation and rewinding in the standard model.

Category / Keywords: public-key cryptography / signature

Publication Info: Accepted by International Journal of Network Security, ISSN 1816-353X (Print) , ISSN 1816-3548 (Online) http://isrc.nchu.edu.tw/ijns/

Date: received 20 Dec 2005, last revised 11 Feb 2006

Contact author: kwwei at ie cuhk edu hk

Available format(s): PDF | BibTeX Citation

Version: 20060212:053355 (All versions of this report)

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