As I've revealed in my last Patreon post, I've been working on adding end-to-end encryption APIs into Mastodon as an upgrade to the direct message system.
Any and all technical details available at the moment are here:
https://github.com/tootsuite/mastodon/pull/13820
An implementation guide for app developers is being worked on.
@Gargron Would using the Signal Protocol (the double ratchet algorithm) an option ?
I feel like the more we use widely used audited algorithms, the safer we are.