downloadbrowseZeroCoder's crackme #12

Download, 845 b (password:
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Difficulty: 6 - Hard, for very professionals only
Platform: Unspecified/other
Language: Unspecified/other

Published: 01. Sep, 2000
Downloads: 2107


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Discussion and comments

03. May 2005
Hello :) I've tried to bruteforce the algo with numbers and a dictionnary, no luck.
Is there anything to do beside bruteforcing ? (it would take years...)
03. May 2005
Well, judging from the rating the autour has set for it, therefore bf it is not very applicable, and do you think bf was the way ?, then i think you misunderstood the purpose of the challense, break the protection by explaining how it works, not just to get a serial or whatever it wants, i suggest you analyse it more (i.e. static analysis), and good luck.
03. May 2005
Well... I know how the algo works, but i can't figure out how to reverse it. It compute a hash from the name, therefore it seems impossible to reverse it. I will try some other way to break it an other day :p
04. May 2005
hi crackers-brothers. why you won't use random bruteforce attak?

tips: true password of 10chars
04. May 2005
Heh ... bruteforcing...

Current Serial: 0QB6YmyrNC Rate: 415910 Serial/sec
Current Serial: Ab3QBCgH81 Rate: 417196 Serial/sec

It will take me 60000years for the worst case :) maybe i will be very lucky and have it in 2 years !

I feel stupid :)
17. May 2005
perhaps there is a shortcut, like in zerocoders #11 which had a 16-byte key ?
18. May 2005
well, i had a look. i don't see any shortcuts at the moment. i tried a bruteforce using the output of jtr with a big set of rules and didn't manage to crack it. my general bruteforcer for this is a lot slower than yours (even taking an early exit strategy). i was hoping to see some correlation between input bits and output bits and use a more intelligent approach but i can't find one....
18. May 2005
This was my idea:
the serial length is 10 chars, the function procuce a hash of 10 bits.
I start with a choosen serial, hash it, generate a serial from the hash (and this is *very* fast), hash it, ... and so on.
I log a serial every 60secs in a file and an other program that i launch manually verifies if the main program has not gone into a loop.

I've stopped because it looked endless... maybe there is something smart to notice ! ( oh ! maybe not... )

I will look it again in a while, i will have a fresh look on it ;)

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