Bubble captcha-a start of the new direction of text captcha scheme development

Abstract

CAPTCHA, A Completely Automated Public Turing test to tell Computers and Humans Apart, is well-known system widely used in all sorts of internet services around the world designated to secure the web from an automatic malicious activity. For almost two decades almost every system utilize a simple approach to this problem containing a transcription of distorted letters from image to a text field. The ground idea is to use imperfection of Optical Character Recognition algorithms against the computers. The development of Optical Character recognition algorithms leads only to state, where the CAPTCHA schemes become more complex and human users have a great dificulty with the transcription. This paper aims to present a new way of development of CAPTCHA schemes based more a human perception. The goal of this work is to implement new Captcha scheme and assess human capability to read unusual fonts newer seen before.