We must stop trying to fix the user to achieve security. We’ll never get there, and research toward those goals just obscures the real problems. Usable security does not mean “getting people to do what we want.” It means creating security that works, given (or despite) what people do. It means security solutions that deliver on users’ security goals without­ — as the 19th-century Dutch cryptographer Auguste Kerckhoffs aptly put it­ — “stress of mind, or knowledge of a long series of rules.”

Source: Security Design: Stop Trying to Fix the User – Schneier on Security