1. A method, implemented by a computer, comprising: responsive to a request by a user to access a secured device, a computer performing a first search for facial images of a first human person using a plurality of tags, the plurality of tags having first properties related to the first human person; selecting, by the computer, a first facial image of the first human person from results retrieved by the first search; modifying, by the computer, the first properties of the plurality of tags to create second properties that are different from the first properties; performing, by the computer, a second search for facial images of other human persons based on the second properties; selecting, by the computer, a plurality of additional facial images of the other human persons retrieved by the second search; presenting, on a physical display, a palette of randomized facial images including the first facial image together with the plurality of additional facial images; responsive to selection by the user of the first facial image from the palette, granting the request to access the secured device; and responsive to selection by the user of any of the plurality of additional facial images, denying the request to access the secured device.