nostr:npub1h0uj825jgcr9lzxyp37ehasuenq070707pj63je07n8mkcsg3u0qnsrwx8 curious that you put 6 as the recommended max group size for Signal groups. What are the performance downsides to having a Signal group of say 20 members versus an MLS group also of 20 members?
Discussion
A small group is essentially a two-party encrypted group. If there are 20 people in the group, when Alice sends a group message, she is actually sending 19 separate one-to-one messages (encrypted with the Signal protocol) to the other members. If the relay requires stamps, group messages will consume more stamps. This limits the maximum number of members a small group can support, but a few dozen members are still manageable. In the Signal protocol used for small groups, the ratchet responsible for post-compromise security advances faster than in MLS, so its post-compromise security is stronger.
Got it, thanks. So if didn't care about the stamp fees then in theory you could have 20 or 30 members and you wouldn't see much of a performance difference versus 5 or 6 members, is that right? It's only when you got over 50 or maybe over 100 that is starts to break down due to the protocol itself?
I think 20–30 group members should be fine. But we haven’t actually tested it, so we’d love to hear your feedback on your real usage experience.