The "game," developed by Stanford University student Hristo Bojinov, has players pressing the S, D F, J, K and L keys on their keyboards as corresponding symbols fall from the top of the screen to the bottom, as seen above. During a standard 45 minute play session, nearly 4,000 "notes" are generated and entered by the player, 80 percent of which are actually part of a cryptographic sequence. By the time the session is over, the subject has "learned" a 30-character password, though it is supposedly impossible for them to actually know what it is.
In order to "enter" the password, the subject plays a round of the game in which their 30 character password is randomly jumbled with other 30-character sequences. The subject subconsciously trained on their specific password would statistically perform better on those sequences rather than the sequences belonging to other passwords, thus verifying their identity.
Unfortunately, Bojinov's subconscious encryption engine isn't playable online at present. Maybe that's for the best, though -- we're not sure how ready we are to be implanted with unknowable knowledge.