Paper 2021/1407
A Concrete Treatment of Efficient Continuous Group Key Agreement via Multi-Recipient PKEs
Keitaro Hashimoto, Shuichi Katsumata, Eamonn Postlethwaite, Thomas Prest, and Bas Westerbaan
Abstract
Continuous group key agreements (CGKAs) are a class of protocols that can provide strong security guarantees to secure group messaging protocols such as Signal and MLS. Protection against device compromise is provided by commit messages: at a regular rate, each group member may refresh their key material by uploading a commit message, which is then downloaded and processed by all the other members. In practice, propagating commit messages dominates the bandwidth consumption of existing CGKAs.
We propose Chained CmPKE, a CGKA with an asymmetric bandwidth cost: in a group of
Metadata
- Available format(s)
-
PDF
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Major revision. ACM CCS 2021
- Keywords
- secure messagingcontinuous group key agreementpost-quantum assumptions(committing) multi-recipient PKE
- Contact author(s)
-
hashimoto k au @ m titech ac jp
shuichi katsumata @ aist go jp
ewp @ cwi nl
thomas prest @ pqshield com
bas @ westerbaan name - History
- 2021-10-24: received
- Short URL
- https://ia.cr/2021/1407
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2021/1407, author = {Keitaro Hashimoto and Shuichi Katsumata and Eamonn Postlethwaite and Thomas Prest and Bas Westerbaan}, title = {A Concrete Treatment of Efficient Continuous Group Key Agreement via Multi-Recipient {PKEs}}, howpublished = {Cryptology {ePrint} Archive, Paper 2021/1407}, year = {2021}, url = {https://eprint.iacr.org/2021/1407} }