Yi Xu, Gerardo Reynaga, Sonia Chiasson, Jan-Michael Frahm, Fabian Monrose, Paul C. van Oorschot. Security and Usability Challenges of Moving-Object CAPTCHAs: Decoding Codewords in Motion. In Tadayoshi Kohno, editor, Proceedings of the 21th USENIX Security Symposium, Bellevue, WA, USA, August 8-10, 2012. pages 49-64, USENIX Association, 2012. [doi]
Abstract is missing.