There was a comment here complaining that Matrix is a failure as an open protocol because encryption in Matrix is too complex and hard and PFS is overrated and "why can't we have a simple protocol for chat like Wireguard is for VPNs"... but it got deleted while i as writing my reply. I'll post the reply anyway:<p>Matrix without encryption is as simple as it gets - e.g. here was a younger, happier me writing a working client in 8 lines of bash: <a href="https://news.ycombinator.com/item?id=20948530">https://news.ycombinator.com/item?id=20948530</a><p>With encryption, inevitably things get way more complicated - especially in a decentralised network which needs to be byzantine fault tolerant. As you say, we've successfully simplified this by providing best-in-class implementations like matrix-rust-sdk-crypto - which i'd argue is the equivalent to Wireguard (which under the hood is a bunch of gnarly crypto, even if the API it exposes it simple).<p>In the end, encrypting messaging is just way harder than a VPN. The encryption hooks need to know the membership of the room (as users), the membership of the room (as devices), verify identities of all devices and their users to prevent MITM, verify that only the right devices can be added to the room, handle accessing history for new logins and new joiners, handle backing up history if you log out of all devices, handle receiving msgs if you log out of all devices, handle encrypted push notifs and allow multiple processes (push, share extension, etc) to share the same crypto state, scale to thousands of devices, etc etc.<p>Meanwhile if you simplify that by removing PFS - sure, some of it gets better ("the room history gets encrypted by a static password!") but then breaching that secret from any client at any point trivially leaks the whole history of the room.<p>In terms of "Matrix as an open protocol isn't very successful", i suggest taking a look at <a href="https://2024.matrix.org/watch/" rel="nofollow">https://2024.matrix.org/watch/</a> for the zeitgeist from a few weeks ago. It's working for some folks at least.