Key Tuple Filtering LED Cipher

led_key_tuple_filtering.py

setGF2(4, 0b10011)

# define fault equations
faults_a = [[0, 4, 8, 12], [3, 7, 11, 15], [2, 6, 10, 14], [1, 5,  9, 13]]
faults_d = [[1, 5, 9, 13], [0, 4,  8, 12], [3, 7, 11, 15], [2, 6, 10, 14]]
faults_c = [[2, 6, 10, 14], [1, 5, 9, 13], [0, 4,  8, 12], [3, 7, 11, 15]]
faults_b = [[3, 7, 11, 15], [2, 6, 10, 14], [1, 5, 9, 13], [0, 4, 8,  12]]

coefs = {'a': [4, 8, 0xB, 2],
 'b': [1, 6, 0xE, 2],
 'c': [2, 5, 0xA, 0xF],
 'd': [2, 6, 9, 0xB]}


sxis = {}
for z in range(0, 4):
 for y in [faults_a, faults_b, faults_c, faults_d]:
  eq = y[z]
  sxi = []
  if y == faults_a:
      cur = 'a'
  if y == faults_b:
      cur = 'b'
  if y == faults_c:
      cur = 'c'
  if y == faults_d:
      cur = 'd'

  for i in range(0, 0xF + 1):
      sxi.append(set({}))
  for i in range(0x0, 0xF + 1):
      for j in range(0x0, 0xF + 1):
          for k in range(0x0, 0xF + 1):
              for l in range(0x0, 0xF + 1):
                  s = calculate_fault_equation([cipher[eq[0]], cipher[eq[1]], cipher[eq[2]], cipher[eq[3]]],
                                               [i, j, k, l],
                                               [cipherf[eq[0]], cipherf[eq[1]], cipherf[eq[2]], cipherf[eq[3]]],
                                               z)

                  sxi[multGF2(find_inverse(coefs[cur][z]), s)].add((i, j, k, l))
  sxis[(cur, z)] = sxi