They are referring to in-transit message over Internet as virtually indecipherable: Nothing a court warrant can't get directly from their servers.
Moxie also "rolled his own crypto". "Rolling your own crypto" is typically used disparagingly by those who claim moral or intellectual superiority over the competition. The Signal Protocol was rolled by someone, yes? The version of MTProto that had vulnerabilities discovered was deprecated many years ago.
Most people think of “private” as between the conversation parties, not everyone in the conversation, the company, and any government with leverage on them.
Encryption at rest prevents from some intrusion attacks but does absolutely nothing against a warrant if the government has leverage.
(Just to clarify: I like Telegram. I just don't like Durov very much and the way he positions Telegram as the superior messenger in every way, even though it obviously isn't when it comes to encryption in particular.)
I did not claim that.
When I wrote:
> Telegram disguises itself as encrypted chat app
I meant exactly that.
