Captcha, Turing test, labeled-image captcha, computer security


Captcha (Completely Automated Public Turing test to tell Computers and Humans Apart) is a widely used online security tool that ensures that a computer program is not posing as a human user. While smart programs with advanced image processing capability have already cracked picture based captcha systems there is a need for making the test harder. This paper presents a design prototype of a simplified type of labeled-image captcha where a picture of a common animal or household item is marked with a number of different labels and the users will be asked to provide the correct label for specific parts of the picture. Due to human’s familiarity with body shapes and part names of such common pictures, they will easily identify a specific organ/parts of the picture. Such labeled-image captcha tests are expected to be very easy for human users regardless of their culture, age, gender, educational background and other discriminations but tough for the bots and automated computer programs.





To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.