m(x) = 0x11b = 100011011 = x^8 + x^4 + x^3 + x + 1m(x) = (x^3) * a(x) + (x^4 + x^3 + x + 1)
a(x) = 0x20 = 00100000 = x^5
1 0 0 0 1 1 1 1 0 1 1
1 1 0 0 0 1 1 1 1 1 1
1 1 1 0 0 0 1 1 0 0 1
1 1 1 1 0 0 0 1 1 0 0
SBOX(20) = 1 1 1 1 1 0 0 0 * 1 + 0 = 1
0 1 1 1 1 1 0 0 1 1 1
0 0 1 1 1 1 1 0 0 1 0
0 0 0 1 1 1 1 1 0 0 1