## CryptoDB

### Paper: Let a Non-barking Watchdog Bite: Cliptographic Signatures with an Offline Watchdog

Authors: Sherman S. M. Chow Alexander Russell Qiang Tang Moti Yung Yongjun Zhao Hong-Sheng Zhou DOI: 10.1007/978-3-030-17253-4_8 Search ePrint Search Google PKC 2019 We study how to construct secure digital signature schemes in the presence of kleptographic attacks. Our work utilizes an offline watchdog to clip the power of subversions via only one-time black-box testing of the implementation. Previous results essentially rely on an online watchdog which requires the collection of all communicating transcripts (or active re-randomization of messages).We first give a simple but generic construction, without random oracles, in the partial-subversion model in which key generation and signing algorithms can be subverted. Then, we give the first digital signature scheme in the complete-subversion model in which all cryptographic algorithms can be subverted. This construction is based on the full-domain hash. Along the way, we enhance the recent result of Russell et al.  (CRYPTO 2018) about correcting a subverted random oracle.
##### BibTeX
@inproceedings{pkc-2019-29282,
title={Let a Non-barking Watchdog Bite: Cliptographic Signatures with an Offline Watchdog},
booktitle={Public-Key Cryptography – PKC 2019},
series={Lecture Notes in Computer Science},
publisher={Springer},
volume={11442},
pages={221-251},
doi={10.1007/978-3-030-17253-4_8},
author={Sherman S. M. Chow and Alexander Russell and Qiang Tang and Moti Yung and Yongjun Zhao and Hong-Sheng Zhou},
year=2019
}