[difficulty: 4] [protection: crc64 control]

I don't want to give away too much yet. The routine is very small. So hopefully very little time reversing and more time keygenning.

EDIT: so it wasn't as hard as I thought! Villani killed it without even knowing the underlying scheme (which, to me, is even more impressive). Artif owned it up also with ease :) Both solutions posted, thanks guys.


  1. Gud one :P. I had a very good idea on what was goin on but then i lost track of everything. I will wait for a gud tut. :)

  2. solved yesterday, i wrote the kgn in asm dude :)
    nice one but i already solved this kind of protection in the past ... :)

  3. @obnoxious: thanks for trying man! poly's and fields are worth studying I think

    @artif: sorry to disappoint :) will try to make something harder soon


thanks for commenting!