4 ms·
Yeah, sorry, I'm not good enough with the math behind crypto enough to have recognized that :( learn something new every day.
by rnovak 12y ago
Yeah, sorry, I'm not good enough with the math behind crypto enough to have recognized that :(
learn something new every day.
- KMag 12y agoPerhaps my notation was a bit too terse. GF2(8) is a Galois field of order Pow(2, 8). The xor operation is addition in a Galois field, so 8-bit xor with 'M' is the same thing as a constant additive shift by 'M' in a Galois field of order Pow(2, 8). So, it's a Caesar shift cipher using the GF2(8) definition of byte addition rather than the standard modulo 256 definition.