Towards making accessible human-interaction proofs more secure and usable

Human-Interaction Proof (HIP) systems are widely used to prevent malicious acts of abusers. Legitimate users, however, are not satisfied with their ease of use. The response of Google to the complaints of difficulty in solving audio reCAPTCHAs was to introduce a much simpler version. But now we are back at the position where we have an accessible and usable but insecure solution. In this work, we propose a pure-text HIP system as an attempt to satisfy accessibility, security, usability requirements altogether. We conduct a user study involving 31 blind or partially sighted users which compares the usability of our pure-text HIP system (SMARTCHA) against Google´s new audio reCAPTCHA. The results of the user study show that visually impaired users enjoy solving SMARTCHA more and prefer it against audio reCAPTCHA.