Paper 2024/1938 Original: eprint.iacr.org/2024/1938 ↗
SoK: On the Security Goals of Key Transparency Systems
Abstract
Key Transparency (KT) systems have emerged as a critical technology for adding verifiability to the distribution of public keys used in end-to-end encrypted messaging services. Despite substantial academic interest, increased industry adoption, and IETF standardization efforts, KT systems lack a holistic and formalized security model, limiting their resilience to practical threats and constraining future development. In this paper, we survey the existing KT literature and present the first cryptographically sound formalization of KT as an ideal functionality. Our work clarifies the underlying assumptions, defines core security properties, and highlights potential vulnerabilities in deployed KT systems. We prove in the Universal Composability framework that our concrete protocol achieves KT security as defined by our formalism. Our KT protocol builds on the latest trends in KT design, guided by the formalization.
Metadata
- Available format(s)
PDF- Category
- Applications
- Publication info
- Preprint.
- History
- 2025-04-24: last updated
- 2024-11-29: published
- Short URL
- https://ia.cr/2024/1938
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2024/1938,
author = {Nicholas Brandt and Mia Filić and Sam A. Markelon},
title = {SoK: On the Security Goals of Key Transparency Systems},
howpublished = {Cryptology {ePrint} Archive, Paper 2024/1938},
year = {2024},
url = {https://eprint.iacr.org/2024/1938}
}