We propose Déjà Vu as a system for user authentication. Déjà Vu is based on the observation that people have an excellent memory for images [Hab70, SCH70, Int80, PC69].
Using Déjà Vu, the user creates an image portfolio, by selecting a subset of images out of a set of sample images. To authenticate the user, the system presents a challenge set, consisting of images. This challenge contains images out of the portfolio. We call the remaining images decoy images. To authenticate, the user must correctly identify the images which are part of her portfolio.
Déjà Vu has three phases: portfolio creation, training, and authentication.