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Didactic Scrambled Egg Cipher Pre-Warmup

 
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Didactic Scrambled Egg Cipher Pre-Warmup
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Meelo



Joined: 25 Apr 2009
Posts: 9

Post Didactic Scrambled Egg Cipher Pre-Warmup Reply with quote
Well, I've been working on this challenge for a few days, but I'm wondering if there's a faster way to get the key than to go through all possibilities (256*256*256*256 is a bit too much for my computer to do in a reasonable amount of time). I think from some tests I did that I'm properly undoing all the other steps in the encryption, but I won't say how because that would give some of the challenge away. I mean, there must be some bits in the final answer that can be prematurely calculated with a single byte of the key, and you could probably somehow optimize on that.
Fri May 01, 2009 12:04 am View user's profile Send private message
Zeta



Joined: 16 Apr 2009
Posts: 62

Post Reply with quote
Brute force worked for me. It doesn't take forever even on a slow machine with an interpreted language. You only have to detect failures fast.
Fri May 01, 2009 7:08 am View user's profile Send private message
Meelo



Joined: 25 Apr 2009
Posts: 9

Post Reply with quote
Failures as in keys that are obviously wrong?

Yeah... I'll try that.
Fri May 01, 2009 8:00 pm View user's profile Send private message
zael



Joined: 29 Sep 2009
Posts: 4

Post Reply with quote
I'm wondering if there's actually a way to reverse the algorithm. The final AND mask which truncates it to 3 bytes is obviously lossy.. but there's many people smarter than me, so I do wonder if it's possible to reverse? I'd be fascinated at the way to reverse it, yet that would be spoiling the solution.
Fri Oct 02, 2009 9:52 pm View user's profile Send private message
Kami



Joined: 04 May 2011
Posts: 10

Post Reply with quote
Well, if you don't just reverse the algorythm for decryption, but understand what it does - visualizing the bits affected by the steps helps - you'll see that there is a simple way not to have to test all 256^4 keys.
Thu Apr 11, 2013 7:46 am View user's profile Send private message
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