def applyCBC(text, DESKey, initialVector, mode):
# convert all parameters into binary
# text = convertToBinary(text)
# DESKey = convertToBinary(DESKey)
# initialVector = convertToBinary(initialVector)
feedback = initialVector
# divide the text into blocks each of size 64 bits
textIntoParts = splitIntoParts(text, 64)
result = []
for i in range(len(textIntoParts)):
if (mode == ENCRYPT):
res = xor(feedback, textIntoParts[i], 64)
feedback = applyDES(res, DESKey, ENCRYPT)
result.append(feedback)
else:
desres = applyDES(textIntoParts[i], DESKey, DECRYPT)
res = ""
if (i == 0):
res = xor(desres, initialVector, 64)
else:
res = xor(desres, textIntoParts[i - 1], 64)
result.append(res)
# convert the binary back to characters
return ("".join(result))
def applyDES(text, key, mode):
# split the text into parts each of size 64
text = splitIntoParts(text, 64)
res = ""
for x in text:
# apply DES for each part
res += DES(x, key, mode)
# return the result
return res
def applyCBC(text, DESKey1, DESKey2, inititalVector, mode):
# convert all parameters into binary
# divide the text into blocks each of size 128 bits
textIntoParts = splitIntoParts(text, 128)
# first generate all keys
DESKey1 = generateKeys(DESKey1)
DESKey2 = generateKeys(DESKey2)
# split the inititalVector into 2 halves each of 64bit length
firstHalf = inititalVector[:64]
lastHalf = inititalVector[64:]
# shift the first half of the initial vector once and second half twice
iv1 = firstHalf[1:] + firstHalf[0]
iv2 = lastHalf[2:] + lastHalf[:2]
# check if encryption or decryption
if (mode == ENCRYPT):
firstHalf, lastHalf = CBCEncryptRound(firstHalf, lastHalf,
textIntoParts[0][:64],
textIntoParts[0][64:], iv1, iv2,
DESKey1, DESKey2)
else:
firstHalf, lastHalf = CBCDecryptRound(lastHalf, firstHalf,
textIntoParts[0][:64],
textIntoParts[0][64:], iv1, iv2,
DESKey1, DESKey2)
# add the first cipher/plaintext into the list
result = [firstHalf + lastHalf]
for i in range(1, len(textIntoParts)):
# shift the first half of the initial vector once and second half twice
iv1 = iv1[1:] + iv1[0]
iv2 = iv2[2:] + iv2[:2]
# check if encryption or decryption
if (mode == ENCRYPT):
firstHalf, lastHalf = CBCEncryptRound(lastHalf, firstHalf,
textIntoParts[i][:64],
textIntoParts[i][64:], iv1,
iv2, DESKey1, DESKey2)
else:
firstHalf, lastHalf = CBCDecryptRound(textIntoParts[i - 1][:64],
textIntoParts[i - 1][64:],
textIntoParts[i][:64],
textIntoParts[i][64:], iv1,
iv2, DESKey1, DESKey2)
# add the cipher/plaintext into the list
result.append(firstHalf + lastHalf)
# return result
return ("".join(result))
def applyDESOnAChannel(channel, h, deskey, mode):
# convert the key to binary string
deskey = convertCharToBinary(deskey)
# iterate through row
for i in range(h):
# first split the row values into groups of 8
channelListIntoParts = splitIntoParts(channel[i], 8)
# then iterate through each group
for k in range(len(channelListIntoParts)):
# convert the list into a binary string
pltxt = convertNumToBinary(channelListIntoParts[k])
# apply the DES for the binary string in encryption mode
cipher = applyDES(pltxt, deskey, mode)
# convert the binary string into number list and create a list of type uint8 for the encrypted binary string
cipherList = numpy.array(convertBinaryToNum(cipher),
dtype=numpy.uint8)
# replace the original value with the cipher value
channelListIntoParts[k] = cipherList
# replace the original row value with the new ciphered value
channel[i] = mergeParts(channelListIntoParts)
# return the channel
return channel
def sBoxes(text):
sBoxesList = [[
[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7],
[0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8],
[4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0],
[15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13],
],
[
[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10],
[3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5],
[0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15],
[13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9],
],
[
[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8],
[13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1],
[13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7],
[1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12],
],
[
[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15],
[13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9],
[10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4],
[3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14],
],
[
[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9],
[14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6],
[4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14],
[11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3],
],
[
[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11],
[10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8],
[9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6],
[4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13],
],
[
[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1],
[13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6],
[1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2],
[6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12],
],
[
[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7],
[1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2],
[7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8],
[2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11],
]]
# firs split the text into 8 parts of 6 bits each
textInto8Parts = splitIntoParts(text, 6)
res = ""
# then apply the sbox for eaxh part
for i, sbox in enumerate(sBoxesList):
# get the row from the first and the last bits
row = int((textInto8Parts[i][0] + textInto8Parts[i][5]), 2)
# get the column from the bits in between first and last bits
col = int(textInto8Parts[i][1:5], 2)
# from the sbox get the result
res += bin(sbox[row][col])[2:].zfill(4)
return res
imgPath = "./geass-gray-img.jpg"
try:
img = cv2.imread(imgPath, 0)
except:
print("Invalid path!")
exit(0)
print("-" * 64)
# ---Encryption---
# get the width and height of the image
w, h = img.shape
print("Encrypting...")
# iterate through each row
for i in range(h):
# first split the row values into groups of 8
imgListIntoParts = splitIntoParts(img[i], 8)
# then iterate through each group
for k in range(len(imgListIntoParts)):
# convert the list into a binary string
pltxt = convertNumToBinary(imgListIntoParts[k])
# apply the CBC for the binary string in encryption mode
cipher = applyCBC(pltxt, deskey, initVect, ENCRYPT)
# convert the binary string into number list and create a list of type uint8 for the encrypted binary string
cipherList = numpy.array(convertBinaryToNum(cipher), dtype=numpy.uint8)
# replace the original value with the cipher value
imgListIntoParts[k] = cipherList
# replace the original row value with the new ciphered value
img[i] = mergeParts(imgListIntoParts)
print("Encryption done!")
# show the encrypted image
cv2.imshow("encrypted image", img)