Photo-Based Authentication Using Social Networks
Lineup, a system that uses the social network graph in Facebook and auxiliary information has underlying mechanism leverages with the concept of CAPTCHAs, programs that are designed to distinguish bots from human users. Lineup extends this functionality to help a Web site ascertain a user's identity or membership in a certain group in order to infer some level of trust. Lineup works by presenting a user with photographs and asking the user to identify subjects in the photo whom a user with the appropriate identity or group membership should know. Many web sites need lightweight authentication schemes to distinguish human from non-human users or to control distribution of content to select groups. However, today's Web access control mechanisms remain fairly cumbersome; administrators must maintain access control lists and user accounts, and users must remember and manage a large collection of passwords. An authentication mechanism known as CAPTCHAs has gained popularity for distinguishing humans from non-humans. CAPTCHAs present automatically generated graphical images to a user that contains some text and asks the user to identify the sequence of characters that is presented in the graphic. Although CAPTCHAs are helpful for distinguishing humans from non-humans, they do not attempt to verify an individual user's identity. CAPTCHAs may be cumbersome in a number of ways and may be too obscure for even a human to decipher.