Messaging Layer Security

last updated: Jul 06, 2025

https://datatracker.ietf.org/wg/mls/about/

The Messaging Layer Security (MLS) protocol, RFC 9420, specifies a key establishment protocol that provides efficient asynchronous group key establishment with forward secrecy (FS) and post-compromise security (PCS) for groups in size ranging from two to thousands.

The MLS WG will maintain the protocol and will work on the following MLS protocol extensions:

An IETF standard for something like the Signal protocol, which is controlled by and only really available from Signal.

There's a list of

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