create beaufort cipher

ciphers/beaufort_cipher.py

@@ -0,0 +1,136 @@
+"""
+Author: Mohit Radadiya
+"""
+
+dict1 = {
+    "A": 0,
+    "B": 1,
+    "C": 2,
+    "D": 3,
+    "E": 4,
+    "F": 5,
+    "G": 6,
+    "H": 7,
+    "I": 8,
+    "J": 9,
+    "K": 10,
+    "L": 11,
+    "M": 12,
+    "N": 13,
+    "O": 14,
+    "P": 15,
+    "Q": 16,
+    "R": 17,
+    "S": 18,
+    "T": 19,
+    "U": 20,
+    "V": 21,
+    "W": 22,
+    "X": 23,
+    "Y": 24,
+    "Z": 25,
+}
+
+dict2 = {
+    0: "A",
+    1: "B",
+    2: "C",
+    3: "D",
+    4: "E",
+    5: "F",
+    6: "G",
+    7: "H",
+    8: "I",
+    9: "J",
+    10: "K",
+    11: "L",
+    12: "M",
+    13: "N",
+    14: "O",
+    15: "P",
+    16: "Q",
+    17: "R",
+    18: "S",
+    19: "T",
+    20: "U",
+    21: "V",
+    22: "W",
+    23: "X",
+    24: "Y",
+    25: "Z",
+}
+
+
+# This function generates the key in
+# a cyclic manner until it's length isn't
+# equal to the length of original text
+def generate_key(message: str, key: str) -> str:
+    """
+    >>> generate_key("THE GERMAN ATTACK","SECRET")
+    'SECRETSECRETSECRE'
+    """
+    x = len(message)
+    i = 0
+    while True:
+        if x == i:
+            i = 0
+        if len(key) == len(message):
+            break
+        key += key[i]
+        i += 1
+    return key
+
+
+# This function returns the encrypted text
+# generated with the help of the key
+def cipherText(message: str, key_new: str) -> str:
+    """
+    >>> cipherText("THE GERMAN ATTACK","SECRETSECRETSECRE")
+    'BDC PAYUWL JPAIYI'
+    """
+    cipher_text = ""
+    i = 0
+    for letter in message:
+        if letter == " ":
+            cipher_text += " "
+        else:
+            x = (dict1[letter] - dict1[key_new[i]]) % 26
+            i += 1
+            cipher_text += dict2[x]
+    return cipher_text
+
+
+# This function decrypts the encrypted text
+# and returns the original text
+def originalText(cipher_text: str, key_new: str) -> str:
+    """
+    >>> originalText("BDC PAYUWL JPAIYI","SECRETSECRETSECRE")
+    'THE GERMAN ATTACK'
+    """
+    or_txt = ""
+    i = 0
+    for letter in cipher_text:
+        if letter == " ":
+            or_txt += " "
+        else:
+            x = (dict1[letter] + dict1[key_new[i]] + 26) % 26
+            i += 1
+            or_txt += dict2[x]
+    return or_txt
+
+
+def main():
+    message = "THE GERMAN ATTACK"
+    key = "SECRET"
+    key_new = generate_key(message, key)
+    cipher_text = cipherText(message, key_new)
+    original_text = originalText(cipher_text, key_new)
+    print("Encrypted Text =", cipher_text)
+    print("Original Text =", original_text)
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()
+    main()