Security of Blind Signatures Revisited

Journal article
(Original article)


Publication Details

Author(s): Schröder D, Unruh D
Journal: Journal of Cryptology
Publisher: Springer New York LLC
Publication year: 2017
Volume: 30
Journal issue: 2
Pages range: 470-494
ISSN: 1432-1378
Language: English


Abstract


We revisit the security definitions of blind signatures as proposed by Pointcheval and Stern (J Cryptol 13(3):361–396, 2000). Security comprises the notions of one-more unforgeability, preventing a malicious user to generate more signatures than requested, and of blindness, averting a malicious signer to learn useful information about the user’s messages. Although this definition is well established nowadays, we show that there are still desirable security properties that fall outside of the model. More precisely, in the original unforgeability definition is not excluded that an adversary verifiably uses the same message m for signing twice and is then still able to produce another signature for a new message m≠ m. Intuitively, this should not be possible; yet, it is not captured in the original definition, because the number of signatures equals the number of requests. We thus propose a stronger notion, called honest-user unforgeability, that covers these attacks. We give a simple and efficient transformation that turns any unforgeable blind signature scheme (with deterministic verification) into an honest-user unforgeable one.



FAU Authors / FAU Editors

Schröder, Dominique Prof. Dr.
Lehrstuhl für Informatik 13 (Angewandte Kryptographie)


How to cite

APA:
Schröder, D., & Unruh, D. (2017). Security of Blind Signatures Revisited. Journal of Cryptology, 30(2), 470-494. https://dx.doi.org/10.1007/s00145-015-9225-1

MLA:
Schröder, Dominique, and Dominique Unruh. "Security of Blind Signatures Revisited." Journal of Cryptology 30.2 (2017): 470-494.

BibTeX: 

Last updated on 2018-08-11 at 13:50