Paper 2022/1128
On the (im)possibility of ElGamal blind signatures
Abstract
In the current paper we investigate the possibility of designing secure blind signature scheme based on ElGamal signature equation. We define the generalized construction and analyze its security. We consider two types of schemes with the proposed construction, that cover all existing schemes. For schemes of the first type we provide generic ROS-style attack that violates unforgeability in the parallel setting. For schemes of the second type we prove that they do not provide either blindness, or unforgeability. As the result, we prove that all known ElGamal blind signature schemes are not secure. Moreover, these results show that the existence of secure ElGamal blind signature scheme is potentially possible only for small set of signature equations and requires the non-standard way of generating the first component of the signature.
Metadata
- Available format(s)
-
PDF
- Category
- Public-key cryptography
- Publication info
- Published elsewhere. CTCrypt 2022 Preproceedings
- Keywords
- ElGamal signature scheme blind signature scheme ROS attack
- Contact author(s)
- babueva @ cryptopro ru
- History
- 2022-08-31: approved
- 2022-08-30: received
- See all versions
- Short URL
- https://ia.cr/2022/1128
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2022/1128,
author = {Liliya Akhmetzyanova and Evgeny Alekseev and Alexandra Babueva and Stanislav Smyshlyaev},
title = {On the (im)possibility of {ElGamal} blind signatures},
howpublished = {Cryptology {ePrint} Archive, Paper 2022/1128},
year = {2022},
url = {https://eprint.iacr.org/2022/1128}
}
