Back-of-the-envelope math: 50 characters x 8 bits = 400 bits of entropy Even if you account for not having backspaces and linfeeds in the password, he could s

Back-of-the-envelope math: 50 characters x 8 bits = 400 bits of entropy Even if you account for not having backspaces and linfeeds in the password, he could still easily have 256 bits of entropy. Even with Moore's law, a strong algo like AES-256 is generally considered to be uncrackable, assuming the algorithm and the implementation don't have any flaws.