Cryptology ePrint Archive: Report 2009/307

Anonymous Signatures Revisited

Vishal Saraswat and Aaram Yun

Abstract: We revisit the notion of the anonymous signature, first formalized by Yang, Wong, Deng and Wang, and then further developed by Fischlin, and Zhang and Imai. We present a new formalism of anonymous signature, where instead of the message, a part of the signature is withheld to maintain anonymity. We introduce the notion unpretendability to guarantee infeasibility for someone other than the correct signer to pretend authorship of the message and signature. Our definition retains applicability for all previous applications of the anonymous signature, provides stronger security, and is conceptually simpler. We give a generic construction from any ordinary signature scheme, and also show that the short signature scheme by Boneh and Boyen can be naturally regarded as such a secure anonymous signature scheme according to our formalism.

Category / Keywords: public-key cryptography / anonymous signature, signature, anonymity, unpretendability

Publication Info: A previous version is to be published in ProvSec 2009

Date: received 25 Jun 2009, last revised 12 Oct 2009

Contact author: aaramyun at gmail com

Available formats: PDF | BibTeX Citation

Note: We revised security definitions and modified the result about Boneh-Boyen accordingly. Also we reformulated our constructions in terms of commitment schemes.

Version: 20091012:171027 (All versions of this report)

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