Rascal999's Rascal999's [windows] crackme challenge! [Cryptography]
| Download encrypt.zip, 23 kb (password: crackmes.de) Browse contents of encrypt.zip Your challenge is to decrypt the crackme file using anything you want. I have provided the file used to encrypt/decrypt messages.
Difficulty: 7 - Very hard | RatingWaiting for at least 3 votes View profile of Rascal999 » |
Solutions
Solution by MR.HAANDI, published 10. jul, 2012; download (64 kb), password: crackmes.de or browse.
MR.HAANDI has not rated this crackme yet.
Discussion and comments
| zart 13. Jun 2008 | For anyone who may have been confused, the encryption routine in the provided program doesn't read a file, it reads whatever you enter on the "Type>" line - then encrypts it with your two keys and saves it to a file. Might be a little confusing for ESL people since it wasn't listed in ReadMe :) |
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| Rascal999 Author 13. Jun 2008 | woops, I'll make sure to fully document my crackmes in future. Thanks zart |
| MR.HAANDI 07. Jul 2012 | After 1049 days trying nearly 10^18 key combinations the computing cluster got the result: pass1 = 756384985 pass2 = 999345234 Congratulations on cracking my encryption. I bet you brute forced ;P As you may have determined pass1 was 756384985 and pass2 was 999345234... Just kidding, simple meet in the middle attack with about 2^32 iterations. Fun as a riddle, but the algorithm is weak using less than 3 passwords. |
| Rascal999 Author 07. Jul 2012 | Wow, you have me at a loss for words ;) how long did it take? With a MITM attack, did you just use one password or..? |
| MR.HAANDI 08. Jul 2012 | With some probable assumptions it takes ~ 184 seconds on my machine to find a password pair. I have submitted my solution, so the details about the attack are explained there. |
| Dcoder 10. Jul 2012 | The description is simpler if you recognize the LCG is only used as the seed for Mersenne Twister. |
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