Lelik

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Welcome to Wikipedia, Lelik! My name is Ryan, aka Acetic Acid. I noticed that you were new and haven't received any messages yet. I just wanted to see how you were doing. Wikipedia can be a little intimidating at first, since it uses different formatting than other sites that use HTML and CSS. In the long run, though, you'll find that the WikiSyntax is a lot easier and faster than those other ways. Here are a few links to get you started:

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I hope you enjoy contributing to Wikipedia. We can use all the help we can get! Have a nice day. Sincerely, Acetic Acid 09:09, August 26, 2005 (UTC)

Common Scrambling Algorithm

Hi Lelik,

I was reading your contribution to the Common Scrambling Algorithm :

" While CSA algorithm uses 64-bit keys, in reality only 48 bytes of key are unknown, since bytes 3 and 7 are used as checksum bytes and may be easily recalculated. This fact allows practical space-time tradeoff attack when 32 bits are brute-forced, 16 bits are calculated with memory tables built from chipertext and 16 bits calculated as checksum with running time O(2¹⁶)+O(2³²) which can be less then a second if implemented in FPGA hardware or on scalable architecture like cell processor.

"

Im currently exploring an attack on the CSA algorithm using an FPGA. I was wondering if you could reference where you found the information about bytes 3 and 7 being checksums or if you could explain how to calculate them. This would, as you say, take a great load off the calculations and make the attack more practical.

Regards,

Aldebarn42

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