Spoken captcha: A captcha system for blind users

Today, the Internet is used to offer different services to users. Most of these services are designed for human users, but unfortunately some computer programs are designed which abuse these services. CAPTCHA (completely automated public Turing test to tell computers and human apart) systems are designed to automatically distinguish between human users and computer programs and block such computer programs. Most of current CAPTCHA methods are using visual patterns and hence blind users cannot use them. In this paper, we propose a new CAPTCHA method which is designed for blind people. In this method, a small sound clip is played for the user and he/she is asked to say a word. Then the user response - which is a speech file - is checked to be the requested word and also not generated by a computer. This method does not require any screen and can be used easily by non-blind and blind users.