Security of blind signatures revisited

Authored book
(Volume of book series)

Publication Details

Author(s): Schröder D, Unruh D
Publication year: 2012
Title of series: Public Key Cryptography - PKC 2012
Pages range: 662-679
ISBN: 9783642300561
Language: English


We revisit the definition of unforgeability of blind signatures as proposed by Pointcheval and Stern (Journal of Cryptology 2000). Surprisingly, we show that this established definition falls short in two ways of what one would intuitively expect from a secure blind signature scheme: It is not excluded that an adversary submits the same message m twice for signing, and then produces a signature for m′ ≠ m. The reason is that the forger only succeeds if all messages are distinct. Moreover, it is not excluded that an adversary performs k signing queries and produces signatures on k + 1 messages as long as each of these signatures does not pass verification with probability 1. Finally, we propose a new definition, honest-user unforgeability, that covers these attacks. We give a simple and efficient transformation that transforms any unforgeable blind signature scheme (with deterministic verification) into an honest-user unforgeable one. © 2012 International Association for Cryptologic Research.

FAU Authors / FAU Editors

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

How to cite

Schröder, D., & Unruh, D. (2012). Security of blind signatures revisited.

Schröder, Dominique, and Dominique Unruh. Security of blind signatures revisited. 2012.


Last updated on 2018-11-12 at 13:50