Making CAPTCHAs Clickable

Authors: Richard Chow, Philippe Golle, Markus Jakobsson, Lusha Wang and Xiaofeng Wang

We show how to convert regular keyboard-entry CAPTCHAs into clickable CAPTCHAs. The goal of this conversion is to simplify and speed-up the entry of the CAPTCHA solution, to minimize user frustration and permit the use of CAPTCHAs on devices where they would otherwise be unsuitable. We show how to obtain a secure clickable CAPTCHA that is well suited for use on cell phones. We support the practical viability of our approach by results from a user study, and an analysis of its security guarantees.