simpleSubDictionaryHacker.py

# Simple Substitution Dictionary Hacker, http://inventwithpython.com/hacking (BSD Licensed)
import pyperclip, simpleSubKeyword, detectEnglish

SILENT_MODE = False

def main():
    myMessage = r"""SJITDOPIQR: JIR RIQMUNQRO AY P WDQC QCR NRSMRQN JT A SJITDORO QJ CRMNRGT AY S. -PHAMJNR ADRMSR"""

    brokenCiphertext = hackSimpleSubDictionary(myMessage)

    if brokenCiphertext == None:
        # hackSimpleSubDictionary() will return the None value if it was unable to hack the encryption.
        print('Hacking failed. Unable to hack this ciphertext.')
    else:
        # The plaintext is displayed on the screen. For the convenience of the user, we copy the text of the code to the clipboard.
        print('Copying broken ciphertext to clipboard:')
        print(brokenCiphertext)
        pyperclip.copy(brokenCiphertext)


def hackSimpleSubDictionary(message):
    print('Hacking with %s possible dictionary words...' % (len(detectEnglish.ENGLISH_WORDS) * 3))

    # Python programs can be stopped at any time by pressing Ctrl-C (on Windows) or Ctrl-D (on Mac and Linux)
    print('(Press Ctrl-C or Ctrl-D to quit at any time.)')

    tryNum = 1

    # brute-force by looping through every possible key
    for key in detectEnglish.ENGLISH_WORDS:
        if tryNum % 100 == 0 and not SILENT_MODE:
            print('%s keys tried. (%s)' % (tryNum, key))

        decryptedText = simpleSubKeyword.decryptMessage(key, message)

        if detectEnglish.getEnglishCount(decryptedText) > 0.20:
            # Check with the user to see if the decrypted key has been found.
            print()
            print('Possible encryption hack:')
            print('Key: ' + str(key))
            print('Decrypted message: ' + decryptedText[:100])
            print()
            print('Enter D for done, or just press Enter to continue hacking:')
            response = input('> ')

            if response.upper().startswith('D'):
                return decryptedText

        tryNum += 1
    return None

if __name__ == '__main__':
    main()