[simias]

In particular none of the attacks described in TFA (Known Plaintext, Chosen Plaintext and Chosen Ciphertext) are possible within the frame of their contest (since Telegram controls all inputs).

Yesterday someone blogged an example of a completely broken cryptosystem that would still pass Telegram's challenge with the same limitations: http://www.thoughtcrime.org/blog/telegram-crypto-challenge/

[StavrosK]

That's Moxie Marlinspike, developer of TextSecure.

[Beltiras]

With a very valid challenge.

[raverbashing]

It may even be possible to factor the RSA Key

More to the point, KPA,CPA, etc are very important, and systems should be definitely tested against them, but in real attacks, they may not be available