Nimbus_plaintexts.py

def create_plaintexts():
    sdiff = list('0' + '1' * (62) + '0')  # 011110 <-- (n - 2) 1's
    diff = int(''.join(sdiff), 2)  # 011110 <-- (n - 2) 1's = 2^63 - 2
    assert diff == 2**63 - 2
    plaintexts = []
    for i in range(32):
        binp = ['0']
        for i in range(62):
            binp.append(str(random.randint(0, 1))) # We create random binary numbers that start and end with 0s
        binp.append('0')
        p = ''.join(binp)  # binary string of plaintext

        xorp = int(p, 2) ^ diff
        bxorp = list(f'{xorp:064b}') # plaintexts that are XORed with the differential
        assert int(p, 2) ^ int(''.join(bxorp), 2) == diff

        # plaintext, plaintext xor diff
        plaintexts.append([p, ''.join(bxorp)])

        # plaintext, complement MSB of plaintext
        binp = comp(binp, 0)
        bxorp = comp(bxorp, 0)
        plaintexts.append([''.join(binp), ''.join(bxorp)])

        # plaintext, complement MSB AND LSB of plaintext
        binp = comp(binp, -1)
        bxorp = comp(bxorp, -1)
        plaintexts.append([''.join(binp), ''.join(bxorp)])

        # plaintext, complement LSB of plaintext
        binp = comp(binp, 0)
        bxorp = comp(bxorp, 0)
        plaintexts.append([''.join(binp), ''.join(bxorp)])
    return plaintexts