Security and Usability: Designing Secure Systems That People Can Use (Repost)

Human factors and usability issues have traditionally played a limited role in security research and secure systems development. Security experts have largely ignored usability issues--both because they often failed to recognize the importance of human factors and because they lacked the expertise to address them.
But there is a growing recognition that today's security problems can be solved only by addressing issues of usability and human factors. Increasingly, well-publicized security breaches are attributed to human errors that might have been prevented through more usable software. Indeed, the world's future cyber-security depends upon the deployment of security technology that can be broadly used by untrained computer users.
Still, many people believe there is an inherent tradeoff between computer security and usability. It's true that a computer without passwords is usable, but not very secure. A computer that makes you authenticate every five minutes with a password and a fresh drop of blood might be very secure, but nobody would use it. Clearly, people need computers, and if they can't use one that's secure, they'll use one that isn't. Unfortunately, unsecured systems aren't usable for long, either. They get hacked, compromised, and otherwise rendered useless.