downloadbrowseOffice Jesus's Fun KeygenMe #2

Download fkgm2-OJ.zip, 25 kb (password: crackmes.de)
Browse contents of fkgm2-OJ.zip

Here's a simple crypto keygenme.

Rules:
1) Keygen + Tutorial is the ultimate goal
2) Self-Keygenning and Phishing are more than welcome
3) Patching is acceptable as a last resort

Please report any bugs...

Good luck,
oJ

Difficulty: 3 - Getting harder
Platform: Windows
Language: Assembler

Published: 14. Jan, 2015
Downloads: 467

Rating

Votes: 3
Crackme is nothing special.

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Solutions

Solution by chalter, published 08. feb, 2015; download (25 kb), password: crackmes.de or browse.

chalter has not rated this crackme yet.

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Discussion and comments

Coderess
15. Jan 2015		Hey bro, where is Fun KeygenMe#1? :)
ragdog
18. Jan 2015		This is a nice keygenme
but i have solved it by T4you on 03 Jan
chalter
28. Jan 2015		The modular exponentiation algorithm starting at 405380 was funky to work through and understand how it works. Very weird way of exponentiation! Is there a name for the algorithm or did you work it out yourself to obscure it?
Herz3h
28. Jan 2015		Does this require one to know SHA-1 or no?
Office Jesus
Author
29. Jan 2015		@Coderess: That one I don't think is worthy of posting here. I don't like it as much as this one.

@chalter: This uses drizz's library for the modular arithmetic. If you want to know more about that particular implementation, he has documentation available... somewhere. I designed everything else _outside_ the library, and nothing was obscured too heavily. I'm sure someone will provide a tutorial explaining how everything works. You can also message me for more information.

@Herz3h: You don't need to know _how_ SHA-1 works as long as you know what it is and can recognize it.
tamaroth
Moderator
03. Feb 2015		I liked how you've hardcoded part of the serial as a discrete log.

Thanks for fun kgme!
adwi32
04. Feb 2015		I can say I've done it, and learned alot of how RSA work in a process. Its a shame how little I know about this the most important crypto today. Thanks!
Herz3h
25. Feb 2015		Wow i just read the solution, no way i could have solved it......

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