e-yes/coursera_stanford_cryptography_practice_quiz_1.py

## coursera_stanford_cryptography_practice_quiz_1.py
'''
Many Time Pad

Let us see what goes wrong when a stream cipher key is used more than once.
Below are eleven hex-encoded ciphertexts that are the result of encrypting eleven plaintexts with a stream cipher,
all with the same stream cipher key.
Your goal is to decrypt the last ciphertext, and submit the secret message within it as solution.

Hint: XOR the ciphertexts together, and consider what happens when a space is XORed with a character in [a-zA-Z].
'''


CIPHERS = (
    bytearray.fromhex('315c4eeaa8b5f8aaf9174145bf43e1784b8fa00dc71d885a804e5ee9fa40b16349c146fb778cdf2d3aff021dfff5b403b510d0d0455468aeb98622b137dae857553ccd8883a7bc37520e06e515d22c954eba5025b8cc57ee59418ce7dc6bc41556bdb36bbca3e8774301fbcaa3b83b220809560987815f65286764703de0f3d524400a19b159610b11ef3e'),
    bytearray.fromhex('234c02ecbbfbafa3ed18510Abd11fa724fcda2018A1a8342cf064bbde548b12b07df44ba7191d9606Ef4081ffde5ad46a5069d9f7f543bedb9c861bf29c7e205132eda9382b0bc2c5c4b45f919cf3a9f1cb74151f6d551f4480c82b2cb24cc5b028aa76eb7b4ab24171ab3cdadb8356f'),
    bytearray.fromhex('32510ba9a7b2bba9b8005d43a304b5714cc0bb0c8a34884dd91304b8ad40b62b07df44ba6e9d8a2368e51d04e0e7b207b70b9b8261112bacb6c866a232dfe257527dc29398f5f3251a0d47e503c66e935de81230b59b7afb5f41afa8d661cb'),
    bytearray.fromhex('32510ba9aab2a8a4fd06414fb517b5605cc0aa0dc91a8908c2064ba8ad5ea06a029056f47a8ad3306ef5021eafe1ac01a81197847a5c68a1b78769a37bc8f4575432c198ccb4ef63590256e305cd3a9544ee4160ead45aef520489e7da7d835402bca670bda8eb775200b8dabbba246b130f040d8ec6447e2c767f3d30ed81ea2e4c1404e1315a1010e7229be6636aaa'),
    bytearray.fromhex('3f561ba9adb4b6ebec54424ba317b564418fac0dd35f8c08d31a1fe9e24fe56808c213f17c81d9607cee021dafe1e001b21ade877a5e68bea88d61b93ac5ee0d562e8e9582f5ef375f0a4ae20ed86e935de81230b59b73fb4302cd95d770c65b40aaa065f2a5e33a5a0bb5dcaba43722130f042f8ec85b7c2070'),
    bytearray.fromhex('32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd2061bbde24eb76a19d84aba34d8de287be84d07e7e9a30ee714979c7e1123a8bd9822a33ecaf512472e8e8f8db3f9635c1949e640c621854eba0d79eccf52ff111284b4cc61d11902aebc66f2b2e436434eacc0aba938220b084800c2ca4e693522643573b2c4ce35050b0cf774201f0fe52ac9f26d71b6cf61a711cc229f77ace7aa88a2f19983122b11be87a59c355d25f8e4'),
    bytearray.fromhex('32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd90f1fa6ea5ba47b01c909ba7696cf606ef40c04afe1ac0aa8148dd066592ded9f8774b529c7ea125d298e8883f5e9305f4b44f915cb2bd05af51373fd9b4af511039fa2d96f83414aaaf261bda2e97b170fb5cce2a53e675c154c0d9681596934777e2275b381ce2e40582afe67650b13e72287ff2270abcf73bb028932836fbdecfecee0a3b894473c1bbeb6b4913a536ce4f9b13f1efff71ea313c8661dd9a4ce'),
    bytearray.fromhex('315c4eeaa8b5f8bffd11155ea506b56041c6a00c8a08854dd21a4bbde54ce56801d943ba708b8a3574f40c00fff9e00fa1439fd0654327a3bfc860b92f89ee04132ecb9298f5fd2d5e4b45e40ecc3b9d59e9417df7c95bba410e9aa2ca24c5474da2f276baa3ac325918b2daada43d6712150441c2e04f6565517f317da9d3'),
    bytearray.fromhex('271946f9bbb2aeadec111841a81abc300ecaa01bd8069d5cc91005e9fe4aad6e04d513e96d99de2569bc5e50eeeca709b50a8a987f4264edb6896fb537d0a716132ddc938fb0f836480e06ed0fcd6e9759f40462f9cf57f4564186a2c1778f1543efa270bda5e933421cbe88a4a52222190f471e9bd15f652b653b7071aec59a2705081ffe72651d08f822c9ed6d76e48b63ab15d0208573a7eef027'),
    bytearray.fromhex('466d06ece998b7a2fb1d464fed2ced7641ddaa3cc31c9941cf110abbf409ed39598005b3399ccfafb61d0315fca0a314be138a9f32503bedac8067f03adbf3575c3b8edc9ba7f537530541ab0f9f3cd04ff50d66f1d559ba520e89a2cb2a83'),
    bytearray.fromhex('32510ba9babebbbefd001547a810e67149caee11d945cd7fc81a05e9f85aac650e9052ba6a8cd8257bf14d13e6f0a803b54fde9e77472dbff89d71b57bddef121336cb85ccb8f3315f4b52e301d16e9f52f904')
    )
KEY = bytearray(b'\x66\x39\x6e\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') # I left only first 3 bytes

def xor_bytearray(a, b, replace_unreadable_with_dot=True):
    res = bytearray()
    length = min(len(a), len(b))
    for i in range(0, length):
        c1 = a[i:i+1]
        c2 = b[i:i+1]
        res = res + bytes([ord(c1) ^ ord(c2)])
    pb = bytearray()
    for byte_ in res:
        if byte_ > ord(b'0') and byte_ < ord(b'z'):
            pb += bytes([byte_])
        elif byte_ == 0:
            pb += b'#'
        else:
            if replace_unreadable_with_dot:
                pb += b'.'
            else:
                pb += bytes([byte_])
    print(pb)

def main():
    print('Stage1:')
    for i in range(0, len(CIPHERS)-1): # Hmm, not-Pythonic way is useful (sometimes)
        for j in range(i, len(CIPHERS)):
            if i != j:
                print('Comparing %d and %d' % (i, j))
                xor_bytearray(CIPHERS[i], CIPHERS[j])
    print('Stage2:')
    for c in CIPHERS:
        xor_bytearray(c, KEY, False)

if __name__ == '__main__':
    main()

## output:
##
## Stage1:
## Comparing 0 and 1
## bytearray(b'..L..NW....O.R...B..M...OH.T..#HN..A...MT......E..MO:#SC#NC....RF.....#..EC.....R..tN....M.U.O.NT7....CST.H..#.M')
## Comparing 0 and 2
## bytearray(b'..EC..C.A....GT..O..M.#.Y]ZQW#.HN..A..U.R.........KR.EC..ND....#.A...RO.H.A#..B..RB..W...#.O...')
## Comparing 0 and 3
## bytearray(b'..EC..P...#..TT..O.#...RBH.AW...KQ......T.#.P.....GT?.#...K.L..#....O.ST..P....#.T.ER....E.#..GAT......#..C....I..R..G.....M..r?....Ph;....')
## Comparing 0 and 4
## bytearray(b'..UC..NA.C...TT..#.#.B.RSTA#..T.A.U....MF.##P.T....W?.#...C....Z..C..RS#..L...B..RB..W...CAr...N....N..M..N....#..R..I....')
## Comparing 0 and 5
## bytearray(b'..E..NA..C#..##..E.U..E.RHET....P..ACT..A.O.....R.GL;EK...#....E..C...ET..O.U...##]\\T...HS.S....T...N..A#OW....#....EK...E#ENR7..E..F.A....')
## Comparing 0 and 6
## bytearray(b'..E..NA..C#..##..E.U..E.YAAO....H.OA...MT...P.....]#..EC..V....E..C##RU..EB.#..E.OCVEW..HB.E..GT..A.....T.N.A..ET....#.....RHSr..#R3O>.#...')
## Comparing 0 and 7
## bytearray(b'#######...T..ET..I#.M...RT.T..T.H..A..U.N...#.T..SO#..O..NB..S.SF....RA..EC......S.XO..T.O.E.O.R..A..#DE..I....E..RHEa.#M6.A@I.')
## Comparing 0 and 8
## bytearray(b'.E....V...Y..Y]HEE#.....I^[#....M.U.....SC\\M....#.ZH:..C..M.#.OAF.....D..##...B..NTGA.#..#.E..K#.R.....D..EB...#.....P##.._#LN6O.E..O......')
## Comparing 0 and 9
## bytearray(b'w1H.A.O.....Ro...R.1....O_TR.I\\Z.ACHN........U....ZOw.SC..EA...#..CT.#I#..GN.M.E.O]CI..T.O.E.AG')
## Comparing 0 and 10
## bytearray(b'..EC..C...T..S...EN..XE.HT[#....GQ.A.#..A.O....##_.N2.E.A.S.L..EF...O.O..ET...B..CT')
## Comparing 1 and 2
## bytearray(b'...E.I..U..I..O.....#.....O.H..#####..SC.......A.....E.A.#....#RAS.#.EO.FF....T.A_SaCN...M...E.')
## Comparing 1 and 3
## bytearray(b'...E.I.....E..O.....C#.J.##.H..A.O.N...P#...R..G......SL.O..R..RG...N.SO.I....#.XY#1.......U.YO.#6....@SE.......')
## Comparing 1 and 4
## bytearray(b'...E.O.H.L.A..O..B..YE.J..TT..TC..WK..##....R.MG..C...SS.E#.....E#T.#ES..A....T.A_SaCN....O..T.#B...E.H.M......M')
## Comparing 1 and 5
## bytearray(b'.....#...L.W.R.....YO.N..#P#...A...#EI.H..E....HB....E.E.PC.....T#T...EO#R..Y...R.L.....Y....E.B#...E.O.TT.....M')
## Comparing 1 and 6
## bytearray(b'.....#...L.W.R.....YO.N...T....P..M#...###..R..L...O...#.O..##..N.T..EU..#.#...OFBR..N..Y....KO.H.U...B_#...O...')
## Comparing 1 and 7
## bytearray(b'..L..NW...DT..O.....#.....###.TC...#..SU.#....MI.E.O...N.#...N..##...EA..##.....E^#....N.....#..O.U.....N...#...')
## Comparing 1 and 8
## bytearray(b'.UD.#I....IK..FBA...R.....NT...E..WS...E.HVO...O....#._#.A....E.#..#.#D..EC...T.ECE3...#.M...SCNAe....B.U..E...M')
## Comparing 1 and 9
## bytearray(b'e..#Rc.....EP=.....=I...#.A..A\\.^_A.H........E.R...#M.##.H.O...RO.TO..I..N.R.P.OSBL7.#.N....#.O')
## Comparing 1 and 10
## bytearray(b'...E.E....DM......L.S_N=..NT...N.O.#...E..E....E.IC....RAU..R...#...N.O..#....T#NNE')
## Comparing 2 and 3
## bytearray(b'####.#..E.....#..#..C..E..O.#..A.O.N..Y.....O........MC..O..I..#.O..TA.FC.....T...SP_O...E.O..H')
## Comparing 2 and 4
## bytearray(b'...#...BTT..#.#..O..Yk.E...QO.SC..WK..SC....O.R...E..OC..E.....Z.SL..#..E.....########.#.Cb=...')
## Comparing 2 and 5
## bytearray(b'###R.I..ET...GT....TO.E.....O..A...#ZET...P.....P....#...PD....E.SL..F.FF...C#O..R.IYT..NS...#.')
## Comparing 2 and 6
## bytearray(b'###R.I..ET...GT....TO.E.#...G..P..M#..EC...#O......R.H.A.O.....E.TL..#..EF....EC...CH#..NB....H')
## Comparing 2 and 7
## bytearray(b'..EC..C.E.H...#....##<.#..O.H.SC...#..#.......R..H.R.R...#...V.SAS..##..DF....U...SMBR.A.O5..E.')
## Comparing 2 and 8
## bytearray(b'.HMP.#..T.E....AB...R2.....QS..E..WS..T..YCT.........SOA#A....EAAP.#.E..R.A...#....RLT...#....D')
## Comparing 2 and 9
## bytearray(b't<.EN...C...N.X.....I.......YI[.^_A.W.E......G......SA.A.H.R...#.FLO.R..I..N.YRC...VDN.A.O...KH')
## Comparing 2 and 10
## bytearray(b'####..#.E#H...S#..U.SqE2...QU..N.O.#..R...P......DE..V..NU..I..EAK..TM#.EF....#....')
## Comparing 3 and 4
## bytearray(b'...#...O.R...##..O.#.E.#..TAO.E..RE....P..#.##L#..I.#.#.....A..Z..O.NA#T......T...SP_O....Dr..E.B...O..M.......I###.#.....')
## Comparing 3 and 5
## bytearray(b'###R.I..#R#..TT....U..DC.#P.O..#.H.NNR....O.H...O.#..MK...K#E..E..O.A..#....E....TL.....C..S..RM#...O..A.N.....I..L.L....T..C_E..I...E.....R....')
## ...skipping...
## bytearray(b'.HMP.#....Y....PR......T..NAS....EE......I\\NA..........L....L.SAG...C..U..P..#T...E......E.E...AAS.##..D...R...I.#C.......DMACDp.I...C?...#R...N')
## Comparing 3 and 9
## bytearray(b't<.EC......#X;X...#1...I..A.YWMS[.SGC.......SA......H.SL...SA..#..ODW..T...H.R.E..L....U#.#E.W#')
## Comparing 3 and 10
## bytearray(b'####....#.T...S...D.._Dw..NAU....#.N......O.I....^I...E.O...#..EG...#..R.I.#..T...E')
## Comparing 4 and 5
## bytearray(b'...R.O.U.#...TT..E.U.FAC...T#.R...YKHY.H..O.H.C.U.I..OK...C......##..F.T....N.O..R.IYT..R.I....BB...#....E..#..#..L.L....R')
## Comparing 4 and 6
## bytearray(b'...R.O.U.#...TT..E.U.FAC..#O..A....K...#....##L...SW..ES7.........#..#..#A....EC...CH#9.R.R7..E..#R.O..AM.#.I..EO.H..I....')
## Comparing 4 and 7
## bytearray(b'..UC..NT.EW...#.#I..YW.E.#TT..##..PK..SU....P.#..YAW..O..E.#.L#.E#E..#...A..#.U...SMBR.A..W7.T....R.H.O......#.E..#nL...E.')
## Comparing 4 and 8
## bytearray(b'.O]P...F#EZ....TOE...Y.T...#..H...#....E.R\\MA.G...T....S......I.E.R..E....L...#....RLT...CK7..IN.E..O#.....T...#.#C1......')
## Comparing 4 and 9
## bytearray(b'y;.ED..I.I..N;X.#R.1.C.I...R.F.QQB.BE.......SAC...T.H.SS...I#..Z..#I.R.#...I.GRC...VDN.A..D7.ZE')
## Comparing 4 and 10
## bytearray(b'...#...U.TW...S..EB...Aw.#.#..I..RAK...E..O.I.H..U#...E.P...A...E.E.NM..#A....#....')
## Comparing 5 and 6
## bytearray(b'########################..........C#BN.H..A.H...O#.L.H.E..V....#..#..F.S.R..U..U.O...T..#.....RXH.N.O..MTA..I..EW...TK.#.U....E#.ES...E....N.O..#...E.....TFBR..U..#1....I..')
## Comparing 5 and 7
## bytearray(b'..E..NA.#ET..ET....TO.H.#.P#..R....#DST...A...C.FW.L.R...PB..C..T#E..F.N.R..N....SL....EP....E.^O.N.H.H..V.....E..LA#...Ps.....')
## Comparing 5 and 8
## bytearray(b'.HM..I...EY..Y]YP#.C..P....T......YSYA#..T.W....R....SGE..M...R.T.R....U..O.O.O..N...#..GS....^.AA..O....R.H...#....Y....G_E...T.#....E....#.#.RD.........Z.')
## Comparing 5 and 9
## bytearray(b't<..Ec...I..Oo.....d..T......GZS@XO..D....N..I#.Y...LA.E..ES...E..#S...T...MOY.U.O#....EC....KR')
## Comparing 5 and 10
## bytearray(b'###R.E.##TT..S...#SI.\\#4...T.....H.#^T..#.#.....R[I..V..E.S.E..#T.E.A..R.R..A.O..C.')
## Comparing 6 and 7
## bytearray(b'..E..NA.#ET..ET....TO.H...T...A.#.J#..EU.##.P.L..W.#...N.O...N..N.E..#...#.....M..R..R.OP..#.KF...#...EIN...O..#N#HLTa..Q.....R')
## Comparing 6 and 8
## bytearray(b'.HM..I...EY..Y]YP#.C..P....O.......S...E.HRTA......H..I#...#..M.N.R..E...EB...EG.....T..GB.#...T.EP.#.#HU..DF#.EE....P....ER..DT.EP5#.#...#N.O.OD...Y.......')
## Comparing 6 and 9
## bytearray(b't<..Ec...I..Oo.....d..T......RIBXI..O.#.....SA.....OT..#3..E...E..#T.R...N.R.T.#.#...N.OC..#.E#')
## Comparing 6 and 10
## bytearray(b'###R.E.##TT..S...#SI.\\#4...O.....Y[#...E..A.I....[SN..#Rg..#R..#N.E.OM..##....EO...')
## Comparing 7 and 8
## bytearray(b'.E....V..#.....PO.#.R.....NT..H...PS..T..HRP..G..I.H..CN.A...YI.#....E...EC...U.#.E....N.O.#.SJR.MP...E....R...E..C_Y1.#N4DA...')
## Comparing 7 and 9
## bytearray(b'w1H.A.O...S.H.X.#...I.....A..E.QXYF.I.E......YC..P.OW..N.H.I.R.SO.EN.R...N.O.S.M..L....#.#.#..F')
## Comparing 7 and 10
## bytearray(b'..EC..C.#.#...S...N.SMH2.#NT..I..I.#..R...A...H...AN....GU..TT..#.#.TM...#....U...E')
## Comparing 8 and 9
## bytearray(b'at@.R.....^.E6QFO..........R.C@W]U.ZT.....]E.L....#.M._#...E..TAO.RO......GF#RRG.......N.O.#.].')
## Comparing 8 and 10
## bytearray(b'.HMP........#.ZAG#N..CP...##.....EAS...#.M.C....#ET...IRN..#L.H.#...C....ET...#...#')
## Comparing 9 and 10
## bytearray(b't<.ES.....S.E<....D..YT>...R.SA\\W.W.S.....N..P...\\T.E..RT..EA..EO.EYW....N.H.NRO...')
## Stage2:
## bytearray(b'We can factor the number 15 with quantum computers. We can also factor the number<!l-4LguA\x8c\xe7\xdck\xc4\x15V\xbd\xb3k\xbc')
## bytearray(b'Euler would probably enjoy that now his theorem becomes a corner stone of crypto 10\x18c-J}d\x0c\x82\xb2\xcb$\xcc[\x02\x8a\xa7n\xb7')
## bytearray(b'The nice thing about Keeyloq is now we cryptographers can drive a lot of fancy cancy carsA\xaf\xa8\xd6a\xcb')
## bytearray(b'The ciphertext produced by a weak encryption algorithm looks as good as ciphertexh0)\x7f,Af~\x04\x89\xe7\xda}\x83T\x02\xbc\xa6p\xbd')
## bytearray(b"You don\'t want to buy a set of car keys from a guy who specializes in stealing cancy chro\x02\xcd\x95\xd7p\xc6[@\xaa\xa0e\xf2")
## bytearray(b'There are two types of cryptography - that which will keep secrets safe from your<|0y7Iv=\x12\x84\xb4\xcca\xd1\x19\x02\xae\xbcf\xf2')
## bytearray(b'There are two types of cyptography: one that allows the Government to use brute fsb:hcQ|=\x03\x9f\xa2\xd9o\x83AJ\xaa\xf2a\xbd')
## bytearray(b'We can see the point where the chip is unhappy if a wrong bit is sent and consumeo04b1@3m\x0e\x9a\xa2\xca$\xc5GM\xa2\xf2v\xba')
## bytearray(b'A (private-key)  encryption scheme states 3 algorithms, namely a procedure for geru+l7L}zA\x86\xa2\xc1w\x8f\x15C\xef\xa2p\xbd')
## bytearray(b' The Concise OxfordDictionary (2006) de\xef\xac\x81nes crypto as the art of  writing o r ss|/d-B3~\x0e\x89\xa2\xcb*\x83')
## bytearray(b'The<REMOVED. WHY NOT TO TRY A BIT HARDER?>')
	'''
	Many Time Pad

	Let us see what goes wrong when a stream cipher key is used more than once.
	Below are eleven hex-encoded ciphertexts that are the result of encrypting eleven plaintexts with a stream cipher,
	all with the same stream cipher key.
	Your goal is to decrypt the last ciphertext, and submit the secret message within it as solution.

	Hint: XOR the ciphertexts together, and consider what happens when a space is XORed with a character in [a-zA-Z].
	'''


	CIPHERS = (
	bytearray.fromhex('315c4eeaa8b5f8aaf9174145bf43e1784b8fa00dc71d885a804e5ee9fa40b16349c146fb778cdf2d3aff021dfff5b403b510d0d0455468aeb98622b137dae857553ccd8883a7bc37520e06e515d22c954eba5025b8cc57ee59418ce7dc6bc41556bdb36bbca3e8774301fbcaa3b83b220809560987815f65286764703de0f3d524400a19b159610b11ef3e'),
	bytearray.fromhex('234c02ecbbfbafa3ed18510Abd11fa724fcda2018A1a8342cf064bbde548b12b07df44ba7191d9606Ef4081ffde5ad46a5069d9f7f543bedb9c861bf29c7e205132eda9382b0bc2c5c4b45f919cf3a9f1cb74151f6d551f4480c82b2cb24cc5b028aa76eb7b4ab24171ab3cdadb8356f'),
	bytearray.fromhex('32510ba9a7b2bba9b8005d43a304b5714cc0bb0c8a34884dd91304b8ad40b62b07df44ba6e9d8a2368e51d04e0e7b207b70b9b8261112bacb6c866a232dfe257527dc29398f5f3251a0d47e503c66e935de81230b59b7afb5f41afa8d661cb'),
	bytearray.fromhex('32510ba9aab2a8a4fd06414fb517b5605cc0aa0dc91a8908c2064ba8ad5ea06a029056f47a8ad3306ef5021eafe1ac01a81197847a5c68a1b78769a37bc8f4575432c198ccb4ef63590256e305cd3a9544ee4160ead45aef520489e7da7d835402bca670bda8eb775200b8dabbba246b130f040d8ec6447e2c767f3d30ed81ea2e4c1404e1315a1010e7229be6636aaa'),
	bytearray.fromhex('3f561ba9adb4b6ebec54424ba317b564418fac0dd35f8c08d31a1fe9e24fe56808c213f17c81d9607cee021dafe1e001b21ade877a5e68bea88d61b93ac5ee0d562e8e9582f5ef375f0a4ae20ed86e935de81230b59b73fb4302cd95d770c65b40aaa065f2a5e33a5a0bb5dcaba43722130f042f8ec85b7c2070'),
	bytearray.fromhex('32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd2061bbde24eb76a19d84aba34d8de287be84d07e7e9a30ee714979c7e1123a8bd9822a33ecaf512472e8e8f8db3f9635c1949e640c621854eba0d79eccf52ff111284b4cc61d11902aebc66f2b2e436434eacc0aba938220b084800c2ca4e693522643573b2c4ce35050b0cf774201f0fe52ac9f26d71b6cf61a711cc229f77ace7aa88a2f19983122b11be87a59c355d25f8e4'),
	bytearray.fromhex('32510bfbacfbb9befd54415da243e1695ecabd58c519cd4bd90f1fa6ea5ba47b01c909ba7696cf606ef40c04afe1ac0aa8148dd066592ded9f8774b529c7ea125d298e8883f5e9305f4b44f915cb2bd05af51373fd9b4af511039fa2d96f83414aaaf261bda2e97b170fb5cce2a53e675c154c0d9681596934777e2275b381ce2e40582afe67650b13e72287ff2270abcf73bb028932836fbdecfecee0a3b894473c1bbeb6b4913a536ce4f9b13f1efff71ea313c8661dd9a4ce'),
	bytearray.fromhex('315c4eeaa8b5f8bffd11155ea506b56041c6a00c8a08854dd21a4bbde54ce56801d943ba708b8a3574f40c00fff9e00fa1439fd0654327a3bfc860b92f89ee04132ecb9298f5fd2d5e4b45e40ecc3b9d59e9417df7c95bba410e9aa2ca24c5474da2f276baa3ac325918b2daada43d6712150441c2e04f6565517f317da9d3'),
	bytearray.fromhex('271946f9bbb2aeadec111841a81abc300ecaa01bd8069d5cc91005e9fe4aad6e04d513e96d99de2569bc5e50eeeca709b50a8a987f4264edb6896fb537d0a716132ddc938fb0f836480e06ed0fcd6e9759f40462f9cf57f4564186a2c1778f1543efa270bda5e933421cbe88a4a52222190f471e9bd15f652b653b7071aec59a2705081ffe72651d08f822c9ed6d76e48b63ab15d0208573a7eef027'),
	bytearray.fromhex('466d06ece998b7a2fb1d464fed2ced7641ddaa3cc31c9941cf110abbf409ed39598005b3399ccfafb61d0315fca0a314be138a9f32503bedac8067f03adbf3575c3b8edc9ba7f537530541ab0f9f3cd04ff50d66f1d559ba520e89a2cb2a83'),
	bytearray.fromhex('32510ba9babebbbefd001547a810e67149caee11d945cd7fc81a05e9f85aac650e9052ba6a8cd8257bf14d13e6f0a803b54fde9e77472dbff89d71b57bddef121336cb85ccb8f3315f4b52e301d16e9f52f904')
	)
	KEY = bytearray(b'\x66\x39\x6e\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00') # I left only first 3 bytes

	def xor_bytearray(a, b, replace_unreadable_with_dot=True):
	res = bytearray()
	length = min(len(a), len(b))
	for i in range(0, length):
	c1 = a[i:i+1]
	c2 = b[i:i+1]
	res = res + bytes([ord(c1) ^ ord(c2)])
	pb = bytearray()
	for byte_ in res:
	if byte_ > ord(b'0') and byte_ < ord(b'z'):
	pb += bytes([byte_])
	elif byte_ == 0:
	pb += b'#'
	else:
	if replace_unreadable_with_dot:
	pb += b'.'
	else:
	pb += bytes([byte_])
	print(pb)

	def main():
	print('Stage1:')
	for i in range(0, len(CIPHERS)-1): # Hmm, not-Pythonic way is useful (sometimes)
	for j in range(i, len(CIPHERS)):
	if i != j:
	print('Comparing %d and %d' % (i, j))
	xor_bytearray(CIPHERS[i], CIPHERS[j])
	print('Stage2:')
	for c in CIPHERS:
	xor_bytearray(c, KEY, False)

	if __name__ == '__main__':
	main()

	## output:
	##
	## Stage1:
	## Comparing 0 and 1
	## bytearray(b'..L..NW....O.R...B..M...OH.T..#HN..A...MT......E..MO:#SC#NC....RF.....#..EC.....R..tN....M.U.O.NT7....CST.H..#.M')
	## Comparing 0 and 2
	## bytearray(b'..EC..C.A....GT..O..M.#.Y]ZQW#.HN..A..U.R.........KR.EC..ND....#.A...RO.H.A#..B..RB..W...#.O...')
	## Comparing 0 and 3
	## bytearray(b'..EC..P...#..TT..O.#...RBH.AW...KQ......T.#.P.....GT?.#...K.L..#....O.ST..P....#.T.ER....E.#..GAT......#..C....I..R..G.....M..r?....Ph;....')
	## Comparing 0 and 4
	## bytearray(b'..UC..NA.C...TT..#.#.B.RSTA#..T.A.U....MF.##P.T....W?.#...C....Z..C..RS#..L...B..RB..W...CAr...N....N..M..N....#..R..I....')
	## Comparing 0 and 5
	## bytearray(b'..E..NA..C#..##..E.U..E.RHET....P..ACT..A.O.....R.GL;EK...#....E..C...ET..O.U...##]\\T...HS.S....T...N..A#OW....#....EK...E#ENR7..E..F.A....')
	## Comparing 0 and 6
	## bytearray(b'..E..NA..C#..##..E.U..E.YAAO....H.OA...MT...P.....]#..EC..V....E..C##RU..EB.#..E.OCVEW..HB.E..GT..A.....T.N.A..ET....#.....RHSr..#R3O>.#...')
	## Comparing 0 and 7
	## bytearray(b'#######...T..ET..I#.M...RT.T..T.H..A..U.N...#.T..SO#..O..NB..S.SF....RA..EC......S.XO..T.O.E.O.R..A..#DE..I....E..RHEa.#M6.A@I.')
	## Comparing 0 and 8
	## bytearray(b'.E....V...Y..Y]HEE#.....I^[#....M.U.....SC\\M....#.ZH:..C..M.#.OAF.....D..##...B..NTGA.#..#.E..K#.R.....D..EB...#.....P##.._#LN6O.E..O......')
	## Comparing 0 and 9
	## bytearray(b'w1H.A.O.....Ro...R.1....O_TR.I\\Z.ACHN........U....ZOw.SC..EA...#..CT.#I#..GN.M.E.O]CI..T.O.E.AG')
	## Comparing 0 and 10
	## bytearray(b'..EC..C...T..S...EN..XE.HT[#....GQ.A.#..A.O....##_.N2.E.A.S.L..EF...O.O..ET...B..CT')
	## Comparing 1 and 2
	## bytearray(b'...E.I..U..I..O.....#.....O.H..#####..SC.......A.....E.A.#....#RAS.#.EO.FF....T.A_SaCN...M...E.')
	## Comparing 1 and 3
	## bytearray(b'...E.I.....E..O.....C#.J.##.H..A.O.N...P#...R..G......SL.O..R..RG...N.SO.I....#.XY#1.......U.YO.#6....@SE.......')
	## Comparing 1 and 4
	## bytearray(b'...E.O.H.L.A..O..B..YE.J..TT..TC..WK..##....R.MG..C...SS.E#.....E#T.#ES..A....T.A_SaCN....O..T.#B...E.H.M......M')
	## Comparing 1 and 5
	## bytearray(b'.....#...L.W.R.....YO.N..#P#...A...#EI.H..E....HB....E.E.PC.....T#T...EO#R..Y...R.L.....Y....E.B#...E.O.TT.....M')
	## Comparing 1 and 6
	## bytearray(b'.....#...L.W.R.....YO.N...T....P..M#...###..R..L...O...#.O..##..N.T..EU..#.#...OFBR..N..Y....KO.H.U...B_#...O...')
	## Comparing 1 and 7
	## bytearray(b'..L..NW...DT..O.....#.....###.TC...#..SU.#....MI.E.O...N.#...N..##...EA..##.....E^#....N.....#..O.U.....N...#...')
	## Comparing 1 and 8
	## bytearray(b'.UD.#I....IK..FBA...R.....NT...E..WS...E.HVO...O....#._#.A....E.#..#.#D..EC...T.ECE3...#.M...SCNAe....B.U..E...M')
	## Comparing 1 and 9
	## bytearray(b'e..#Rc.....EP=.....=I...#.A..A\\.^_A.H........E.R...#M.##.H.O...RO.TO..I..N.R.P.OSBL7.#.N....#.O')
	## Comparing 1 and 10
	## bytearray(b'...E.E....DM......L.S_N=..NT...N.O.#...E..E....E.IC....RAU..R...#...N.O..#....T#NNE')
	## Comparing 2 and 3
	## bytearray(b'####.#..E.....#..#..C..E..O.#..A.O.N..Y.....O........MC..O..I..#.O..TA.FC.....T...SP_O...E.O..H')
	## Comparing 2 and 4
	## bytearray(b'...#...BTT..#.#..O..Yk.E...QO.SC..WK..SC....O.R...E..OC..E.....Z.SL..#..E.....########.#.Cb=...')
	## Comparing 2 and 5
	## bytearray(b'###R.I..ET...GT....TO.E.....O..A...#ZET...P.....P....#...PD....E.SL..F.FF...C#O..R.IYT..NS...#.')
	## Comparing 2 and 6
	## bytearray(b'###R.I..ET...GT....TO.E.#...G..P..M#..EC...#O......R.H.A.O.....E.TL..#..EF....EC...CH#..NB....H')
	## Comparing 2 and 7
	## bytearray(b'..EC..C.E.H...#....##<.#..O.H.SC...#..#.......R..H.R.R...#...V.SAS..##..DF....U...SMBR.A.O5..E.')
	## Comparing 2 and 8
	## bytearray(b'.HMP.#..T.E....AB...R2.....QS..E..WS..T..YCT.........SOA#A....EAAP.#.E..R.A...#....RLT...#....D')
	## Comparing 2 and 9
	## bytearray(b't<.EN...C...N.X.....I.......YI[.^_A.W.E......G......SA.A.H.R...#.FLO.R..I..N.YRC...VDN.A.O...KH')
	## Comparing 2 and 10
	## bytearray(b'####..#.E#H...S#..U.SqE2...QU..N.O.#..R...P......DE..V..NU..I..EAK..TM#.EF....#....')
	## Comparing 3 and 4
	## bytearray(b'...#...O.R...##..O.#.E.#..TAO.E..RE....P..#.##L#..I.#.#.....A..Z..O.NA#T......T...SP_O....Dr..E.B...O..M.......I###.#.....')
	## Comparing 3 and 5
	## bytearray(b'###R.I..#R#..TT....U..DC.#P.O..#.H.NNR....O.H...O.#..MK...K#E..E..O.A..#....E....TL.....C..S..RM#...O..A.N.....I..L.L....T..C_E..I...E.....R....')
	## ...skipping...
	## bytearray(b'.HMP.#....Y....PR......T..NAS....EE......I\\NA..........L....L.SAG...C..U..P..#T...E......E.E...AAS.##..D...R...I.#C.......DMACDp.I...C?...#R...N')
	## Comparing 3 and 9
	## bytearray(b't<.EC......#X;X...#1...I..A.YWMS[.SGC.......SA......H.SL...SA..#..ODW..T...H.R.E..L....U#.#E.W#')
	## Comparing 3 and 10
	## bytearray(b'####....#.T...S...D.._Dw..NAU....#.N......O.I....^I...E.O...#..EG...#..R.I.#..T...E')
	## Comparing 4 and 5
	## bytearray(b'...R.O.U.#...TT..E.U.FAC...T#.R...YKHY.H..O.H.C.U.I..OK...C......##..F.T....N.O..R.IYT..R.I....BB...#....E..#..#..L.L....R')
	## Comparing 4 and 6
	## bytearray(b'...R.O.U.#...TT..E.U.FAC..#O..A....K...#....##L...SW..ES7.........#..#..#A....EC...CH#9.R.R7..E..#R.O..AM.#.I..EO.H..I....')
	## Comparing 4 and 7
	## bytearray(b'..UC..NT.EW...#.#I..YW.E.#TT..##..PK..SU....P.#..YAW..O..E.#.L#.E#E..#...A..#.U...SMBR.A..W7.T....R.H.O......#.E..#nL...E.')
	## Comparing 4 and 8
	## bytearray(b'.O]P...F#EZ....TOE...Y.T...#..H...#....E.R\\MA.G...T....S......I.E.R..E....L...#....RLT...CK7..IN.E..O#.....T...#.#C1......')
	## Comparing 4 and 9
	## bytearray(b'y;.ED..I.I..N;X.#R.1.C.I...R.F.QQB.BE.......SAC...T.H.SS...I#..Z..#I.R.#...I.GRC...VDN.A..D7.ZE')
	## Comparing 4 and 10
	## bytearray(b'...#...U.TW...S..EB...Aw.#.#..I..RAK...E..O.I.H..U#...E.P...A...E.E.NM..#A....#....')
	## Comparing 5 and 6
	## bytearray(b'########################..........C#BN.H..A.H...O#.L.H.E..V....#..#..F.S.R..U..U.O...T..#.....RXH.N.O..MTA..I..EW...TK.#.U....E#.ES...E....N.O..#...E.....TFBR..U..#1....I..')
	## Comparing 5 and 7
	## bytearray(b'..E..NA.#ET..ET....TO.H.#.P#..R....#DST...A...C.FW.L.R...PB..C..T#E..F.N.R..N....SL....EP....E.^O.N.H.H..V.....E..LA#...Ps.....')
	## Comparing 5 and 8
	## bytearray(b'.HM..I...EY..Y]YP#.C..P....T......YSYA#..T.W....R....SGE..M...R.T.R....U..O.O.O..N...#..GS....^.AA..O....R.H...#....Y....G_E...T.#....E....#.#.RD.........Z.')
	## Comparing 5 and 9
	## bytearray(b't<..Ec...I..Oo.....d..T......GZS@XO..D....N..I#.Y...LA.E..ES...E..#S...T...MOY.U.O#....EC....KR')
	## Comparing 5 and 10
	## bytearray(b'###R.E.##TT..S...#SI.\\#4...T.....H.#^T..#.#.....R[I..V..E.S.E..#T.E.A..R.R..A.O..C.')
	## Comparing 6 and 7
	## bytearray(b'..E..NA.#ET..ET....TO.H...T...A.#.J#..EU.##.P.L..W.#...N.O...N..N.E..#...#.....M..R..R.OP..#.KF...#...EIN...O..#N#HLTa..Q.....R')
	## Comparing 6 and 8
	## bytearray(b'.HM..I...EY..Y]YP#.C..P....O.......S...E.HRTA......H..I#...#..M.N.R..E...EB...EG.....T..GB.#...T.EP.#.#HU..DF#.EE....P....ER..DT.EP5#.#...#N.O.OD...Y.......')
	## Comparing 6 and 9
	## bytearray(b't<..Ec...I..Oo.....d..T......RIBXI..O.#.....SA.....OT..#3..E...E..#T.R...N.R.T.#.#...N.OC..#.E#')
	## Comparing 6 and 10
	## bytearray(b'###R.E.##TT..S...#SI.\\#4...O.....Y[#...E..A.I....[SN..#Rg..#R..#N.E.OM..##....EO...')
	## Comparing 7 and 8
	## bytearray(b'.E....V..#.....PO.#.R.....NT..H...PS..T..HRP..G..I.H..CN.A...YI.#....E...EC...U.#.E....N.O.#.SJR.MP...E....R...E..C_Y1.#N4DA...')
	## Comparing 7 and 9
	## bytearray(b'w1H.A.O...S.H.X.#...I.....A..E.QXYF.I.E......YC..P.OW..N.H.I.R.SO.EN.R...N.O.S.M..L....#.#.#..F')
	## Comparing 7 and 10
	## bytearray(b'..EC..C.#.#...S...N.SMH2.#NT..I..I.#..R...A...H...AN....GU..TT..#.#.TM...#....U...E')
	## Comparing 8 and 9
	## bytearray(b'at@.R.....^.E6QFO..........R.C@W]U.ZT.....]E.L....#.M._#...E..TAO.RO......GF#RRG.......N.O.#.].')
	## Comparing 8 and 10
	## bytearray(b'.HMP........#.ZAG#N..CP...##.....EAS...#.M.C....#ET...IRN..#L.H.#...C....ET...#...#')
	## Comparing 9 and 10
	## bytearray(b't<.ES.....S.E<....D..YT>...R.SA\\W.W.S.....N..P...\\T.E..RT..EA..EO.EYW....N.H.NRO...')
	## Stage2:
	## bytearray(b'We can factor the number 15 with quantum computers. We can also factor the number<!l-4LguA\x8c\xe7\xdck\xc4\x15V\xbd\xb3k\xbc')
	## bytearray(b'Euler would probably enjoy that now his theorem becomes a corner stone of crypto 10\x18c-J}d\x0c\x82\xb2\xcb$\xcc[\x02\x8a\xa7n\xb7')
	## bytearray(b'The nice thing about Keeyloq is now we cryptographers can drive a lot of fancy cancy carsA\xaf\xa8\xd6a\xcb')
	## bytearray(b'The ciphertext produced by a weak encryption algorithm looks as good as ciphertexh0)\x7f,Af~\x04\x89\xe7\xda}\x83T\x02\xbc\xa6p\xbd')
	## bytearray(b"You don\'t want to buy a set of car keys from a guy who specializes in stealing cancy chro\x02\xcd\x95\xd7p\xc6[@\xaa\xa0e\xf2")
	## bytearray(b'There are two types of cryptography - that which will keep secrets safe from your<\|0y7Iv=\x12\x84\xb4\xcca\xd1\x19\x02\xae\xbcf\xf2')
	## bytearray(b'There are two types of cyptography: one that allows the Government to use brute fsb:hcQ\|=\x03\x9f\xa2\xd9o\x83AJ\xaa\xf2a\xbd')
	## bytearray(b'We can see the point where the chip is unhappy if a wrong bit is sent and consumeo04b1@3m\x0e\x9a\xa2\xca$\xc5GM\xa2\xf2v\xba')
	## bytearray(b'A (private-key) encryption scheme states 3 algorithms, namely a procedure for geru+l7L}zA\x86\xa2\xc1w\x8f\x15C\xef\xa2p\xbd')
	## bytearray(b' The Concise OxfordDictionary (2006) de\xef\xac\x81nes crypto as the art of writing o r ss\|/d-B3~\x0e\x89\xa2\xcb*\x83')
	## bytearray(b'The<REMOVED. WHY NOT TO TRY A BIT HARDER?>')