A Concept of Captcha Based Dynamic Password

Background: The conventional text passwords are by far the main means of authentication and they will continue to be popular as they are easy to deploy and to use. However, they have been largely exposed to different kind of attacks like guessing, phishing and key-logger attacks. Objective: It is efficient to use both CAPTCHA and text password in a user authentication to create an additional layer of security over the passwords. Captcha and password work side by side and independently in such captcha-assisted systems. Captcha filters out the suspicious programs from the human beings and password recognizes the legitimate user among the human beings. Methods: In this paper, we have suggested a dynamic password scheme combining the traditional text password and captcha. User authentication will be verified by different passwords at different login session based on the captcha presentations. Results: Suggested method does not replace the conventional password process rather than modifying it. Therefore, users’ current sign-in experience is largely preserved. It will be implemented in software alone, increasing the potential for large-scale adoption on the Internet. Conclusion: The scheme is easy to implement and will be useful to improve the security to a great extent.