Comment by maqp

There's nothing slow about AES.

In this context "heavily" means "we can't legally claim it's end-to-end encrypted because it's not".

Also it's not even post quantum, so it's not heavy. Telegram's Diffie-Hellman breaks instantly with a quantum computer large enough to run Shor against it.

Also, the keys sit on the servers' RAM, no matter what they lie. There is no global distributed RAM system, especially one that encrypts data in distributed fashion and works at the negligible latencies that Telegram boasts.