Paper 2024/799
Symmetric Signcryption and E2EE Group Messaging in Keybase
, Georgia Institute of Technology, Georgia Institute of TechnologyAbstract
We introduce a new cryptographic primitive called symmetric signcryption, which differs from traditional signcryption because the sender and recipient share a secret key. We prove that a natural composition of symmetric encryption and signatures achieves strong notions of security against attackers that can learn and control many keys. We then identify that the core encryption algorithm of the Keybase encrypted messaging protocol can be modeled as a symmetric signcryption scheme. We prove the security of this algorithm, though our proof requires assuming non-standard, brittle security properties of the underlying primitives.
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- A major revision of an IACR publication in EUROCRYPT 2024
- DOI
- 10.1007/978-3-031-58734-4_10
- Keywords
- Provable securityReal-world systemsSecure messaging
- Contact author(s)
-
josephjaeger @ gatech edu
akshayakumar @ gatech edu - History
- 2024-05-24: approved
- 2024-05-23: received
- See all versions
- Short URL
- https://ia.cr/2024/799
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2024/799,
author = {Joseph Jaeger and Akshaya Kumar and Igors Stepanovs},
title = {Symmetric Signcryption and {E2EE} Group Messaging in Keybase},
howpublished = {Cryptology ePrint Archive, Paper 2024/799},
year = {2024},
doi = {10.1007/978-3-031-58734-4_10},
note = {\url{https://eprint.iacr.org/2024/799}},
url = {https://eprint.iacr.org/2024/799}
}
