@feld According to german security expert @kuketz in his blog article from 2020 there is at the time no audit for the Telegram MTProto 2.0 protocol.
https://www.kuketz-blog.de/telegram-sicherheit-gibt-es-nur-auf-anfrage-messenger-teil3/
Correct me if that is wrong. The first MTProto was broken in a very amateurish way. The second not audited at all to my knowledge.
I like to believe Telegram being an unattractive target for audits anyways since it's closed source and publicly criticizing tools of the russian state might be bad for your health
#telegram