Humans should be able to think of computers as extensions of their body, as craftsmen do with their tools. Current security models, however, are too unlike those used in human minds---for example, computers authenticate users by challenging them to repeat a secret rather than by continually observing the many subtle cues offered by their appearance and behavior. We propose three lines of research that can be combined to produce cognitive security on computers and other personal devices: imprinting and continuously deployed multi-modal biometrics, self-protection through virtualization and trusted computing, and adjustably autonomous security.
