Even with absolutely perfect systems, which do not exist in practice even when they may exist in math, the humans with the keys are the weakest link. Stolen cre

Even with absolutely perfect systems, which do not exist in practice even when they may exist in math, the humans with the keys are the weakest link. Stolen credentials are the biggest cause of data breaches in enterprise web applications (according the the Verizon DBIR). And even for absolutely perfect humans with impeccable morals, which do not exist as no one is perfect, there is coercion in the form of rubber hose cryptography. There was even a movie about coercion called Firewall with Harrison Ford - http://www.imdb.com/title/tt0408345/ http://www.imdb.com/title/tt0408345/.