Added Trafid Cipher (TheAlgorithms#746)

Author: nowakowsky

ciphers/trafid_cipher.py

@@ -0,0 +1,86 @@
+#https://en.wikipedia.org/wiki/Trifid_cipher
+
+def __encryptPart(messagePart, character2Number):
+ one, two, three = "", "", ""
+ tmp = []
+ 
+ for character in messagePart:
+ tmp.append(character2Number[character])
+
+ for each in tmp:
+ one += each[0]
+ two += each[1]
+ three += each[2]
+ 
+ return one+two+three
+
+def __decryptPart(messagePart, character2Number):
+ tmp, thisPart = "", ""
+ result = []
+
+ for character in messagePart:
+ thisPart += character2Number[character]
+
+ for digit in thisPart:
+ tmp += digit
+ if len(tmp) == len(messagePart):
+ result.append(tmp)
+ tmp = "" 
+
+ return result[0], result[1], result[2]
+
+def __prepare(message, alphabet):
+ #Validate message and alphabet, set to upper and remove spaces
+ alphabet = alphabet.replace(" ", "").upper()
+ message = message.replace(" ", "").upper()
+
+ #Check length and characters
+ if len(alphabet) != 27:
+ raise KeyError("Length of alphabet has to be 27.")
+ for each in message:
+ if each not in alphabet:
+ raise ValueError("Each message character has to be included in alphabet!")
+
+ #Generate dictionares
+ numbers = ("111","112","113","121","122","123","131","132","133","211","212","213","221","222","223","231","232","233","311","312","313","321","322","323","331","332","333")
+ character2Number = {}
+ number2Character = {}
+ for letter, number in zip(alphabet, numbers):
+ character2Number[letter] = number
+ number2Character[number] = letter
+ 
+ return message, alphabet, character2Number, number2Character
+
+def encryptMessage(message, alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period=5):
+ message, alphabet, character2Number, number2Character = __prepare(message, alphabet)
+ encrypted, encrypted_numeric = "", ""
+
+ for i in range(0, len(message)+1, period):
+ encrypted_numeric += __encryptPart(message[i:i+period], character2Number)
+ 
+ for i in range(0, len(encrypted_numeric), 3):
+ encrypted += number2Character[encrypted_numeric[i:i+3]]
+
+ return encrypted
+
+def decryptMessage(message, alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ.", period=5):
+ message, alphabet, character2Number, number2Character = __prepare(message, alphabet)
+ decrypted_numeric = []
+ decrypted = ""
+
+ for i in range(0, len(message)+1, period):
+ a,b,c = __decryptPart(message[i:i+period], character2Number)
+ 
+ for j in range(0, len(a)):
+ decrypted_numeric.append(a[j]+b[j]+c[j])
+
+ for each in decrypted_numeric:
+ decrypted += number2Character[each]
+
+ return decrypted
+
+if __name__ == '__main__':
+ msg = "DEFEND THE EAST WALL OF THE CASTLE."
+ encrypted = encryptMessage(msg,"EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
+ decrypted = decryptMessage(encrypted, "EPSDUCVWYM.ZLKXNBTFGORIJHAQ")
+ print ("Encrypted: {}\nDecrypted: {}".format(encrypted, decrypted))