Пример #1
0
def Encrypt(k, S, SE, SBOX, TBOX, IndexArray, SrtB):
    E = ['' for i in range(4)]
    for i in range(0, LT - 1):
        for j in range(0, LT):
            E[j] = binstr.b_xor(W[j], S[j])
        for j in range(0, LT):
            if (EvenParity(E[j]) == True):
                Rotate_Right(j, SBOX)
            else:
                Rotate_Left(j, SBOX)

            SBOX[2][j] = binstr.b_xor(SBOX[2][j], bin(SrtB[j])[2:].zfill(8))

        Transpose(SBOX)
    E = [str(x) for x in numpy.roll(E, 1)]

    for i in range(0, LT):
        TIndex = transposition_index_generation(TBOX, i)
        #if k==0:
        #    print "E:",TIndex
        while (IndexArray[TIndex % N] != 0):
            TIndex = TIndex + 1
        TIndex = TIndex % N
        #if k==0:
        #    print TIndex
        #    print "E[i] {}".format(int(E[i],2))
        #write E[i] in encrypted file SE in position of TIndex
        SE[TIndex] = int(E[i], 2)
        IndexArray[TIndex] = 1
        SrtB[i] = int(S[i], 2)

    SBOX, TBOX = TBOX, SBOX
    #if k==0:
    #    print " E \n SBOX {}\n TBOX {}".format(SBOX,TBOX)
    return SE, SBOX, TBOX
Пример #2
0
def encryption_key_gen(EKy, Ky, D):
    '''
    Generates 32 Bytes EKy from user input Ky ( >= 16 Bytes ) 
    and D ( MD5 hash of Ky = 16 Bytes )
    '''
    p1 = p2 = p3 = 0
    L1 = len(Ky)
    for i in range(0, 32):
        if(i % 2 == 0):
            Eky[i] = D[p1]
            p1 += 1
        else:
            p4 = p2 + 1
            Eky[i] = binstr.b_xor(binstr.b_xor(D[p2], D[p4]), Ky[(p3) % L1])
            p3 += 1
    return Eky
Пример #3
0
def WORD_generation(SBOX, W):
    '''
    Generates of 1 x LT WORD array by column wise XORing of SBOX 
    ( used for encryption )
    '''
    for i in range(0, LT):
        for j in range(0, LT):
            W[i] = binstr.b_xor(W[i], SBOX[j][i])
Пример #4
0
def Decrypt(SE_N, front_index, SE, SD, SBOX, TBOX, IndexArray, SrtB):

    E = ['' for i in range(4)]
    S = ['' for i in range(4)]

    for i in range(0, LT):
        TIndex = transposition_index_generation(TBOX, i)
        while(IndexArray[TIndex % N] != 0):
            TIndex = TIndex + 1
        TIndex = TIndex % N
        #print i, TIndex, len(SE)
        #write E[i] in encrypted file SE in position of TIndex
        E[i] = SE_N[TIndex]
        #print "E[i] {}".format(E[i])
        IndexArray[TIndex] = 1


    E = [str(x) for x in numpy.roll(E, -1)]
    for i in range(0, LT - 1):

        for j in range(0, LT):
            S[j] = binstr.b_xor(W[j],E[j])
            # print "S[j] {} W[j] {} E[j] {}".format(S[j],W[j],E[j])

        for j in range(0, LT):
            if(EvenParity(E[j]) == True):
                Rotate_Right(j, SBOX)
            else:
                Rotate_Left(j, SBOX)
                

            SBOX[2][j] = binstr.b_xor(SBOX[2][j], bin(SrtB[j])[2:].zfill(8))
        
        Transpose(SBOX)
    
    for i in range(LT):
        # print i,S[i]
        SD[front_index+i] = int(S[i],2)
        SrtB[i] = int(S[i],2)


    SBOX, TBOX = TBOX, SBOX
    # print "D \n SBOX {}\n TBOX {}".format(SBOX,TBOX)
    return SD, SBOX, TBOX