Create vernam_cipher.py

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)

ciphers/vernam_cipher.py

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+def vernam_encrypt(plaintext: str, key: str) -> str:
+ """
+ >>> vernam_encrypt("HELLO","KEY")
+ 'RIJVS'
+ """
+ ciphertext = ""
+ for i in range(len(plaintext)):
+ ct = ord(key[i % len(key)]) - 65 + ord(plaintext[i]) - 65
+ while ct > 25:
+ ct = ct - 26
+ ciphertext += chr(65 + ct)
+ return ciphertext
+
+
+def vernam_decrypt(ciphertext: str, key: str) -> str:
+ """
+ >>> vernam_decrypt("RIJVS","KEY")
+ 'HELLO'
+ """
+ decrypted_text = ""
+ for i in range(len(ciphertext)):
+ ct = ord(ciphertext[i]) - ord(key[i % len(key)])
+ while ct < 0:
+ ct = 26 + ct
+ decrypted_text += chr(65 + ct)
+ return decrypted_text
+
+
+if __name__ == "__main__":
+ from doctest import testmod
+
+ testmod()
+
+ # Example usage
+ plaintext = "HELLO"
+ key = "KEY"
+ encrypted_text = vernam_encrypt(plaintext, key)
+ decrypted_text = vernam_decrypt(encrypted_text, key)
+ print("\n\n")
+ print("Plaintext:", plaintext)
+ print("Encrypted:", encrypted_text)
+ print("Decrypted:", decrypted_text)