Question

Why will this not work to do a 3 rail encryption? How would I make it work? Will it encrypt special characters? The program language Python.

userString=input("What would you like to decrypt and encrypt?: ")

def threeRailEncrypt(plainText):

railOne=""

railTwo=""

railThree=""

for i in range(0,len(plainText),3):

railOne=railOne+plainText[i]

for i in range(1,len(plainText),3):

railTwo=railTwo+plainText[i]

for i in range(2,len(plainText),3):

railThree=railThree+plainText[i]

return railThree+railTwo+railOne

print()

print("Encrypted version:")

print(threeRailEncrypt(userString))

def threeRailDecrypt(cipherText):

thirdLen=len(cipherText)//3

if len(cipherText)%3==2:

x=1

else:

x=0

railThree=cipherText[:thirdLen]

railTwo=cipherText[thirdLen:2*thirdLen+x]

railOne=cipherText[2*thirdLen+x:]

plainText=""

  

for i in range(thirdLen):

plainText+=railOne[i]+railTwo[i]+railThree[i]

if len(cipherText)%3==1:

plainText+=railOne[thirdLen]

if len(cipherText)%3==2:

plainText+=railOne[thirdLen]

plainText+=railTwo[thirdLen]

return plainText

print()

print("Decrypted version:")

print(threeRailDecrypt(threeRailEncrypt(userString)))

Answer 1

userString=input("What would you like to decrypt and encrypt?: ")

# function to encrypr the decrypted text
def threeRailEncrypt(plainText):

   # create empty rails
   railOne=""
   railTwo=""
   railThree=""

   # create rails 
   for i in range(0,len(plainText),4):
      railOne=railOne+plainText[i]

   for i in range(1,len(plainText),2):
      railTwo=railTwo+plainText[i]

   for i in range(2,len(plainText),4):
      railThree=railThree+plainText[i]

   return railOne + railTwo + railThree

print()
print("Encrypted version:")
print(threeRailEncrypt(userString))

# function to decrypt the encrypted text
def threeRailDecrypt(cipherText):

   # creating empty rails
   railOne = [' ' for i in range(len(cipherText))]
   railTwo = [' ' for i in range(len(cipherText))]
   railThree = [' ' for i in range(len(cipherText))]
   j = 0

   # storing the values at the correct positions
   for i in range(0, len(cipherText), 4):
      railThree[i] = cipherText[j]
      j += 1
   
   for i in range(1, len(cipherText), 2):
      railTwo[i] = cipherText[j]
      j += 1
      
   
   for i in range(2, len(cipherText), 4):
      railOne[i] = cipherText[j]
      j += 1    
   
   # recollecting the text
   plainText = ''
   for i in range(len(cipherText)):
      if railThree[i] != ' ':
         plainText += railThree[i]
      if railTwo[i] != ' ':
         plainText += railTwo[i]
      if railOne[i] != ' ':
         plainText += railOne[i]
   
   return plainText

print()
print("Decrypted version:")
print(threeRailDecrypt(threeRailEncrypt(userString)))

FOR HELP PLEASE COMMENT.
THANK YOU.