Without some sort of reproducible builds (which are really finnickey to actually get) this doesn’t really help though. Adding some set of malicious patches before doing the binary release is trivial.

Thanks for the clarification I should have mentioned this. Especially for calls it is actually relevant but I feel like very few people actually use secret chats.

To clarify because this is always a point of confusion whenever the topic comes up. Telegram is, of course, transport encrypted. Someone listening on the wire cannot read your data. It is not end-to-end encrypted, meaning Telegram can always read your messages and can, in principle, give anyone access.

Lovely, the parent comment mentioned blockchain but was since edited… Trust me I would not have brought it up otherwise.

Blockchains have the property of being append-only, so a blockchain is precisely what makes it impossible to delete transactions. That being said, in a distributed system, once the message leaves trusted servers, it is obviously also impossible to delete it.