96 lines
2.8 KiB
Python
96 lines
2.8 KiB
Python
def vigenere_en(ptext, vk):
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result = []
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ptext = ptext.upper()
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vk = vk.upper()
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kl = len(vk)
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for i, ch in enumerate(ptext):
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if ch.isalpha():
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shift = (ord(vk[i % kl]) - ord('A')) % 26
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result.append(chr((ord(ch) - ord('A') + shift) % 26 + ord('A')))
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else:
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result.append(ch)
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return ''.join(result)
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def vigenere_de(ctext, vk):
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result = []
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ctext = ctext.upper()
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vk = vk.upper()
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kl = len(vk)
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for i, ch in enumerate(ctext):
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if ch.isalpha():
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shift = (ord(vk[i % kl]) - ord('A')) % 26
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result.append(chr((ord(ch) - ord('A') - shift) % 26 + ord('A')))
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else:
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result.append(ch)
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return ''.join(result)
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def autokey_en(ptext, ak):
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result = []
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ptext = ptext.upper()
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current_key = ak
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for ch in ptext:
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if ch.isalpha():
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shift = (current_key - ord('A')) % 26
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cipher_char = chr((ord(ch) - ord('A') + shift) % 26 + ord('A'))
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result.append(cipher_char)
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current_key = ord(cipher_char)
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else:
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result.append(ch)
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return ''.join(result)
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def autokey_de(ctext, ak):
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result = []
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ctext = ctext.upper()
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current_key = ak
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for ch in ctext:
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if ch.isalpha():
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shift = (current_key - ord('A')) % 26
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plain_char = chr((ord(ch) - ord('A') - shift) % 26 + ord('A'))
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result.append(plain_char)
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current_key = ord(plain_char)
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else:
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result.append(ch)
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return ''.join(result)
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def operator(argument,ptext,ak,vk):
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match argument:
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case '1':
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print("Vigenere Cipher")
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print("Plaintext: ", ptext)
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print("Vigenere Key: ", vk)
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ctext = vigenere_en(ptext, vk)
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print("Ciphertext: ", ctext)
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print("Decrypted Text: ", vigenere_de(ctext, vk))
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case '2':
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print("Autokey Cipher")
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print("Plaintext: ", ptext)
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print("Auto Key: ", ak)
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ctext = autokey_en(ptext, ak)
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print("Ciphertext: ", ctext)
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print("Decrypted Text: ", autokey_de(ctext, ak))
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case '3':
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print("Goodbye")
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exit()
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case _:
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print("Invalid Choice, please try again.")
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def main():
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ptext = input("Kindly enter your desired plaintext: ")
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vk = input("Kindly enter the Vigenere Key: ")
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ak = int(input("Kindly enter the Autokey: "))
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print("Welcome to the Autokey cipher system.")
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print("Enter your choice of algorithm")
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print("1. Vigenere Cipher")
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print("2. Autokey Cipher")
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print("3. Exit")
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while True:
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op = input("Enter your choice of operation: ")
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operator(op, ptext, ak, vk)
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if __name__ == '__main__':
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main()
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