I tried signal, matrix, Riot, Slack, Discord, Messenger, Hangouts, and Keybase is by far the best option.
It is in an uncertain place though since Zoom bought them and moved its developers to work on Zoom. There has only been one small update to Keybase since zoom purchased them.
While it's not getting updated I don't have any worries about the reliability of its existing security. It's not perfect but it's pretty mature and feature-rich.
It is in an uncertain place though since Zoom bought them and moved its developers to work on Zoom. There has only been one small update to Keybase since zoom purchased them.