[forgottenpass]

OK, but where the hell are they going to get 2.5 months of highly motivated attacks by highly skilled people? All the people I would want looking at this aren't going to waste such a huge chunk of their time analyzing some random phone app trying to make a name for themselves for a chance at a cash reward.

Bug bounties by big name companies that are actually after bugs rather than publicity haven't miraculously made all their software perfect. And they don't have an end date either.

[paveldurov]

I agree with you here. That is why such contests are going to be permanent in Telegram. New contests like this will be launched in March 2014 or earlier if anyone wins earlier. Consider the date for breaking Telegram open.

[forgottenpass]

Your interest rings a bit hollow when you define a very narrow attack surface for the bounty, and dismiss architectural criticism beyond it.