[duskwuff]

Telegram only uses end-to-end encryption for "secret chats" and voice calls. Group chats and standard person-to-person chats are not end-to-end encrypted, and I don't believe Telegram has made any claims to the contrary.

(Encrypted messaging is a hard problem, especially when you have to deal with users with multiple devices which are offline intermittently, or users joining an established group chat. Telegram has taken the sensible approach of not trying to solve this.)

[tptacek]

Encrypted messaging is a solved problem, and even WhatsApp manages end-to-end group chats. Telegram does not, but claims in its FAQ that "All Telegram messages are always securely encrypted" (it is referring explicitly to group messaging). Telegram is far more misleading than Zoom is, but again, Zoom lacks the cheering section. Maybe if they released a ZoomCoin.

[duskwuff]

Fair point on the FAQ. At least they didn't explicitly misuse the term "end-to-end"?

That being said, I'm not certain encryption is an entirely solved problem for the case of multiple devices, including web clients, or for large public groups. (WhatsApp only supports a single client -- their web interface attaches to the phone -- and their group chats are limited to 256 members.) I'm not sure it can be solved under the current model Telegram uses for authorizing devices, as the server can authorize a device to access an account, and any non-secret chats it was involved in, without the involvement of any previously signed-in devices.