Cryptology ePrint Archive: Report 2013/326

Key-Versatile Signatures and Applications: RKA, KDM and Joint Enc/Sig

Mihir Bellare and Sarah Meiklejohn and Susan Thomson

Abstract: This paper introduces key-versatile signatures. Key-versatile signatures allow us to sign with keys already in use for another purpose, without changing the keys and without impacting the security of the original purpose. This allows us to obtain advances across a collection of challenging domains including joint Enc/Sig, security against related-key attack (RKA) and security for key-dependent messages (KDM). Specifically we can (1) Add signing capability to existing encryption capability with zero overhead in the size of the public key (2) Obtain RKA-secure signatures from any RKA-secure one-way function, yielding new RKA-secure signature schemes (3) Add integrity to encryption while maintaining KDM-security.

Category / Keywords: foundations / Signatures, Related-Key attack, Tampering, Key-Dependent Messages, NIZKs

Original Publication (with major differences): Eurocrypt 2014

Date: received 27 May 2013, last revised 9 Feb 2014

Contact author: mihir at eng ucsd edu

Available format(s): PDF | BibTeX Citation

Version: 20140209:134528 (All versions of this report)

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