Yan, Jeff and El Ahmad, Ahmad Salah (2008) Usability of CAPTCHAs or usability issues in CAPTCHA design. In: SOUPS 2008 - Proceedings of the 4th Symposium on Usable Privacy and Security. ACM, USA, pp. 44-52. ISBN 9781605582764
Full text not available from this repository.Abstract
CAPTCHA is now almost a standard security technology, and has found widespread application in commercial websites. Usability and robustness are two fundamental issues with CAPTCHA, and they often interconnect with each other. This paper discusses usability issues that should be considered and addressed in the design of CAPTCHAs. Some of these issues are intuitive, but some others have subtle implications for robustness (or security). A simple but novel framework for examining CAPTCHA usability is also proposed.