http://uwb25d43nnzerbozmtviwn7unn7ku226tpsjyhy5n4st5cf3d4mtflqd.onion/posts/e2ee/index.html
This is straight forward with email, if all project members have the email password and the private PGP key. Applications we do not recommend We do not recommend: Telegram : Telegram has no end-to-end encryption for group chats, and it is opt-in for one-on-one chats. The encryption doesn't use established protocols, and has had cryptographers describe it as "the most backdoor-looking bug I’ve ever seen" .