Paper 2024/879
Consistency-or-Die: Consistency for Key Transparency
, Chalmers University of Technology, University of GothenburgAbstract
In this paper we point out the problem of insufficient tools for protecting against split-view attacks in Key Transparency protocols, and propose a solution to fill the void. We discuss why current approaches are not suitable and then propose a novel notion, GOD-less broadcast, that solves the issue. Like conventional notions of broadcast, GOD-less broadcast guarantees consistency. However, it does not provide Guaranteed Output Delivery (GOD). We provide an efficient realization of this new notion using a hidden committee of randomly selected and initially undisclosed users which endorse the current view. We also introduce and analyze a new concept of a quorum which ensures consistency among all honest active users. Our GOD-less broadcast protocol is practical and applicable to existing large scale Key Transparency systems, e.g. the Key Transparency used in WhatsApp.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Preprint.
- Keywords
- Key TransparencyConsistencyTransparency LogsBroadcast
- Contact author(s)
-
joakim @ hyker io
elenap @ chalmers se
bernardo @ bmdavid com
paul stankovski_wagner @ eit lth se - History
- 2024-06-05: approved
- 2024-06-02: received
- See all versions
- Short URL
- https://ia.cr/2024/879
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2024/879,
author = {Joakim Brorsson and Elena Pagnin and Bernardo David and Paul Stankovski Wagner},
title = {Consistency-or-Die: Consistency for Key Transparency},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/879},
year = {2024},
url = {https://eprint.iacr.org/2024/879}
}
