downloadbrowseBUBlic's Xor 2 Zero

Download Xor_2_Zero_KeygenMe_by_BUBlic.zip, 34 kb (password: crackmes.de)
Browse contents of Xor_2_Zero_KeygenMe_by_BUBlic.zip

I think this one is gonna entertain everyone, who likes keygenning and clean algorithms. No packer/protector, so you understand the routine in a few minutes.

The difficult task is writing a keygen, which:
-doesn't bruteforce
-only uses XOR and AND in his main part (except hash)
-fast/memory efficient (if the problem would be larger)

Difficulty: 3 - Getting harder
Platform: Windows
Language: C/C++

Published: 15. Jun, 2007
Downloads: 626

Rating

Votes: 3
Crackme is nothing special.

Rate this crackme:

Send a message to BUBlic »

View profile of BUBlic »

Solutions

Solution by andrewl.us, published 15. jan, 2009; download (39 kb), password: crackmes.de or browse.

andrewl.us has rated this crackme as awesome.

Submit your solution »

Discussion and comments

hound
16. Jun 2007		hmm, just got to figure out how to go backwards.....
pretty fun though, nice and simple algo, just got to work it out :).
BUBlic
Author
05. Jul 2007		maybe it's more difficult for you than I thought. I give you two "hints".
1. if two bits are equal the XOR of them is always ZERO.
2. the serial is shifted so one bit doesn't change.
hound
17. Jan 2009		Fantastic solution! I was just starting to have a look at this keygen again :)

You may leave your comment, thoughts and discuss this crackme with other reversers here.
Acting childish will not be tolerated.
HTML and such will be left as-is, so don't try.