“A cross-disciplinary team of US neuroscientists and cryptographers have developed a password/passkey system that removes the weakest link in any security system: the human user. It’s ingenious: The system still requires that you enter a password, but at no point do you actually remember the password, meaning it can’t be written down and it can’t be obtained via coercion or torture” writes Sebastian Anthony in this Extreme Tech article Unbreakable crypto: Store a 30-character password in your brain’s subconscious memory, worth of a read. Something akin to playing Guitar Hero they say!
So, can a subconsciously remembered password be unbreakable? Maybe, if you don’t mind the time it’ll take you to sign on.
Then, again, you should consider this from xkck: Through 20 years of effort, we’ve successfully trained everyone to use passwords that are hard for humans to remember, but easy for computers to guess. Four random common but easily remembered words, they claim, is much harder to hack than the antics some of us come up with to encrypt our passwords.