downloadbrowsebrangelito's KeymakeMe #3

Download KeymakeMe3.zip, 12 kb (password: crackmes.de)
Browse contents of KeymakeMe3.zip

KeymakeMe #3

This keygenme should be pretty fun, because it's
kinda unique. The scheme isn't keygennable if you
don't know a valid key already.

Thus, I will give you one:
XXB691C349AD753912BC9E1F9F1587XX

However four of the hexadecimal digits are
missing (they are marked with X). Your objective
is to bruteforce these digits, then use this
serial to keygen other valid serials.

As you'll also notice that the algo really
isn't bruteforcable, at least not without some
limiting modifications..

Good Luck!
/Brangelito

MODERATOR NOTE: you may cap your bruting at 50000 iterations

Difficulty: 2 - Needs a little brain (or luck)
Platform: Windows
Language: C/C++

Published: 22. Jun, 2010
Downloads: 717

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Solutions

Solution by hound, published 08. jul, 2010; download (49 kb), password: crackmes.de or browse.

hound has not rated this crackme yet.

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Discussion and comments

redoC
23. Jun 2010		program freeze, is it intended?
_ghandi_
23. Jun 2010		I've seen variations on this idea in commercial applications and i'll agree that without a starting point, its like searching for a needle in a haystack.
brangelito
Author
23. Jun 2010		Yes, program freeze is intended.
brangelito
Author
23. Jun 2010		Ghandi: Well, it's impossible without a starting point. You have a 1 in 2^128 chance to find the correct serial, if you just pick a random one. :)
_ghandi_
23. Jun 2010		Yep, quite a large keyspace to be searching...
_ghandi_
24. Jun 2010		But 'impossible' is such a big word, i'd be more inclined to use the word 'improbable' because there is still the possibility that it could be discovered/bruteforced without any hints, as small as it is that chance makes it possible.
brangelito
Author
25. Jun 2010		Nobody solved this one yet? :)
hound
28. Jun 2010		All done then. I will write up a solution some time today.
brangelito
Author
28. Jun 2010		Great!

I'm looking forward to your solution!

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