Re:Animation of the AES algorithm
by nitrogen on Tuesday October 12, 2010 @12:54AM
(#1782365)
On step 4, AddRoundKey, shouldn't e5+17 be fc, not f2? Or is AES using something other than simple 8-bit modular arithmetic? It looks like the author did the arithmetic in his/her head, and accidentally used decimal for the second digit (5 + 7 = 12, mod 10 = 2).
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The + in a circle means xor, not plus
That's what I get for learning programming years before entering college. I forget standard mathematical notation, since I always use programming language operators (like ^) in my head. Further, I only checked the first row to make sure it was actual addition, and obviously 0xa0 + 0x04 == 0xa0 ^ 0x04.
I should've just checked here first (includes an image of the slide in question): http://stackoverflow.com/questions/839479/what-does-a-circle...