transpositionBreaker.py

# Transpositional Cipher Breaker
# http://inventwithpython.com/codebreaker (BSD Licensed)

import pyperclip, detectEnglish, transpositionDecrypt

def main():
    # You might want to copy & paste this text from the source code at
    # http://invpy.com/transpositionBreaker.py
    myMessage = """Cb b rssti aieih rooaopbrtnsceee er es no npfgcwu  plri ch nitaalr eiuengiteehb(e1  hilincegeoamn fubehgtarndcstudmd nM eu eacBoltaeteeoinebcdkyremdteghn.aa2r81a condari fmps" tad   l t oisn sit u1rnd stara nvhn fsedbh ee,n  e necrg6  8nmisv l nc muiftegiitm tutmg cm shSs9fcie ebintcaets h  aihda cctrhe ele 1O7 aaoem waoaatdahretnhechaopnooeapece9etfncdbgsoeb uuteitgna.rteoh add e,D7c1Etnpneehtn beete" evecoal lsfmcrl iu1cifgo ai. sl1rchdnheev sh meBd ies e9t)nh,htcnoecplrrh ,ide hmtlme. pheaLem,toeinfgn t e9yce da' eN eMp a ffn Fc1o ge eohg dere.eec s nfap yox hla yon. lnrnsreaBoa t,e eitsw il ulpbdofgBRe bwlmprraio po  droB wtinue r Pieno nc ayieeto'lulcih sfnc  ownaSserbereiaSm-eaiah, nnrttgcC  maciiritvledastinideI  nn rms iehn tsigaBmuoetcetias rn"""

    brokenCiphertext = breakTransposition(myMessage)

    if brokenCiphertext == None:
        print('Failed to break encryption.')
    else:
        print('Copying broken ciphertext to clipboard:')
        print(brokenCiphertext)
        pyperclip.copy(brokenCiphertext)


def breakTransposition(message):
    print('Breaking...')

    # 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.)')

    # brute force by looping through every possible key
    for key in range(1, len(message)):
        print('Trying key #%s...' % (key))

        decryptedText = transpositionDecrypt.decryptMessage(key, message)

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

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

    return None

if __name__ == '__main__':
    main()