Sorry, I'm afraid my original post wasn't very clear. I was describing potential problems with Moxie's intentionally weak protocol, not with Telegram. The hash

Sorry, I'm afraid my original post wasn't very clear. I was describing potential problems with Moxie's intentionally weak protocol, not with Telegram. The hash in question is MD2 used to reduce the 32-byte random secret to a 16-byte shared encryption key. MD2 is weak, but I'm not sure if it matters in this context. As I said above though, I'm also not sure that it doesn't matter.