Telegram is a superior messaging app but it's privacy is questionable. The fact that they keep their encryption protocol hidden is bothersome and they aren't e2ee by default. And as stated before, it's not certain their e2ee is as private as they claim.

[–] selokichtli@lemmy.ml 1 points 1 year ago

IIRC they did publish their encryption protocol, at least a lot of information about it is here. It's true E2EE is not enabled by default.

In the end, both encryption protocols are hidden. We can't really be sure they use what they say they are using in both cases.