Merge pull request #18 from murugan-k-0204/main

Vigenère Cipher python implementation

Author: itspyguru

decrypto/vigenere _cipher.py

@@ -0,0 +1,41 @@
+class VigenereCipher:
+    def __init__(self) -> None:
+        pass
+
+    @staticmethod
+    def encrypt(msg: str, key: str) -> str:
+        msg, key  = msg.upper(), key.upper() 
+        if len(msg) > len(key):
+            # Generates the key in a cyclic manner until it's length equal to the length of text
+            for i in range(len(msg) - len(key)):
+                key += key[i % len(key)]
+        encrypted_words = []
+        curr_key_index = 0
+        for text in msg.split():
+            result = ''
+            for i in range(len(text)):
+                x = (ord(text[i]) + ord(key[curr_key_index])) % 26
+                x += ord('A')
+                result+= chr(x)
+                curr_key_index+=1
+            encrypted_words.append(result)
+        return ' '.join(encrypted_words).lower()
+
+    @staticmethod
+    def decrypt(msg: str,key: str) -> str:
+        msg, key  = msg.upper(), key.upper() 
+        if len(msg) > len(key):
+            # Generates the key in a cyclic manner until it's length equal to the length of msg
+            for i in range(len(msg) - len(key)):
+                key += key[i % len(key)]
+        decrypted_words = []
+        curr_key_index = 0
+        for word in msg.split():
+            result = ''     
+            for i in range(len(word)):
+                x = (ord(word[i]) - ord(key[curr_key_index]) + 26) % 26
+                x += ord('A')
+                result += chr(x)
+                curr_key_index+=1
+            decrypted_words.append(result)
+        return ' '.join(decrypted_words).lower()