Color channel CAPTCHA: A secure scheme for cloud environment

Abstract

Abuse of cloud services consequently unauthorized access to cloud data by malicious software automation is prevented by CAPTCHA. The secure usable mechanism is mandatory for resilience to automate attacks accordingly to create pleasant challenges. In this paper, we propose a novel image-based graphical Color Channel CAPTCHA scheme to distinguish between malware and humans for data security in the cloud environment. This color channel CAPTCHA is designed with 2 X 2 grids of different color channels with micro invisible circles or less visible moving circles. This simple challenge is completed by click on the specified circles in the given order with very less solving time, while compared to the state of the art. The experimental study has been conducted among 41 participants on both usability and performance of color channel CAPTCHA.