[str3wer]

it has been audited, and they said it was a total mess and was full of vulnerabilities

[jeroenhd]

Source? My cursory search hasn't found much wrong with the current protocol, though mtproto 1 relied on some rather weak cryptography which luckily got replaced years ago.

[skrowl]

Audited and found to be a mess is a complete lie. 0 encrypted telegram messages have ever been cracked. Full stop.

They even took some ideas that people in the crypto had pointed out and updated their mtproto protocol to 2.0 https://core.tlgr.org/mtproto

[str3wer]

mess ≠ cracked