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60 lines
1.6 KiB
Python
60 lines
1.6 KiB
Python
def encrypt_scytale_cipher(message: str, key: int) -> str:
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"""
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Encrypts a message using the Scytale Cipher.
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:param message: Text to encrypt.
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:param key: Number of rows (key).
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:return: Encrypted message.
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"""
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message = message.replace(" ", "") # Optional: remove spaces
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ciphertext = [""] * key
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# Distribute characters across rows based on the key
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for i in range(len(message)):
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ciphertext[i % key] += message[i]
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return "".join(ciphertext)
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def decrypt_scytale_cipher(ciphertext: str, key: int) -> str:
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"""
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Decrypts a message encrypted with the Scytale Cipher.
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:param ciphertext: Encrypted text.
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:param key: Number of rows (key).
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:return: Decrypted message.
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"""
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num_cols = -(-len(ciphertext) // key) # Calculate number of columns (round up)
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num_rows = key
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num_shaded_boxes = (num_cols * num_rows) - len(ciphertext) # Extra unused boxes
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plaintext = [""] * num_cols
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col = 0
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row = 0
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# Rebuild the plaintext row by row
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for char in ciphertext:
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plaintext[col] += char
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col += 1
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# Reset column and move to next row if end of column is reached
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if (col == num_cols) or (
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col == num_cols - 1 and row >= num_rows - num_shaded_boxes
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):
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col = 0
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row += 1
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return "".join(plaintext)
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# Example usage
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message = "HELLO WORLD FROM SCYTALE"
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key = 5
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# Encrypt the message
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ciphered = encrypt_scytale_cipher(message, key)
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print("Encrypted:", ciphered)
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# Decrypt the message
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deciphered = decrypt_scytale_cipher(ciphered, key)
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print("Decrypted:", deciphered)
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