Computer Architecture

It is a well-known fact that the expansion of Internet has given rise to many daily activities which are being done online including financial and personal data transactions which has developed the need of security like never before. It has made people realize that the data on the internet must be secured as many types of attacks are increasing day by day with the advancement of technology. So, here the requirement is to ensure that the services are supplied to a legitimate user rather than bots to prevent service abuse. The present article provides such a security from bots with the help of a standard security mechanism called CAPTCHA. A new cognition-based design of CAPTCHA is produced overcoming the limitation of presently available CAPTCHA. Also, a new architecture for producing these CAPTCHA codes randomly is presented in this article so that the differentiation among a legitimate user and Bots can be made. Thus, the major objective of the article is to present an optimum security mechanism for differentiating among humans and Bots.