3rd International Conference on Information Technology in Education and Development ITED2020 129 Enhanced CAPTCHA Based Authentication using Mathematical Operation Olanrewaju Oyenike Mary 1 and Abdulwasiu Adebayo Abdulhafeez 2 1 Department Computer Science, Federal University Dutsinma. 2 Computer Science Department, Federal University Dutsinma. oolanrewaju@fudutsinma.edu.ng ibnwasar@gmail.com. Abstract Despite the fact that many research works have been done on the way to securing documents on websites, attackers are day by day finding means of detecting a way to break all the security methods. One of the ways of these prevention is Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) which is used to protect websites such as E- mail providers, social networks, and online business from unauthorized user. This research work reviewed major text CAPTCHA in existence, and proposed an Enhanced CAPTCHA based authentication using Mathematical operation to provide solutions to most common problem of the existing ones such as inlegibility of character and easy penetration by smart robots. The proposed system based the authentication on random mathematics expression with alteration in the operator for the user to respond to the challenge by supplying the correct answer. The implementation was developed using Visual Basic 2010 and result were presented in this paper. Keywords: security,website, CAPTCHA, mathematical operation I. INTRODUCTION Security is an essential domain and it plays vital role in protecting one’s resources so as to keep them from hackers, theft or the likes. It has been noticed that technology advances every day because many new things are being designed to the extent that machines are now designed to predict or to serve as a Robot which can penetrate into user’s account and manipulate things. Many security methods have been design to curb the problem of insecurity and to protect documents and one of the security ways of protecting users document is using CAPTCHA. The term CAPTCHA was coined in 2003 by Luis Von Ahn , Manuel Blum, Nicholas J. Hopper, and John Langford [15]. The most common type of CAPTCHA (displayed as Version 1.0) was first invented in 1997 by two groups working in parallel. This form of CAPTCHA requires that the user type the letters of a distorted image, sometimes with the addition of an obscured sequence of letters or digits that appears on the screen because the test is administered by a computer [9], in contrast to the standard Turing test that is administered by a human, therefore, a CAPTCHA is sometimes described as a reverse Turing test [8]. This user identification procedure has received many criticisms, especially from people with disabilities, but also from other people who feel that their everyday work is slowed down by distorted words that are difficult to read. It takes the average person approximately 10 seconds to solve a typical CAPTCHA [3]. There are different kinds of CAPTCHA, one of them is text-based CAPTCHA , where user would be requested to supply the text displayed in pictures which computer cannot understand but made easy for human. This research deals with Mathematical operation CAPTCHA based on text to solve the insecurity problem in other to reduce the guessing attacks and increase the simplicity of CAPTCHA password. The proposed algorithm is built on CAPTCHA and mathematical operation. Mathematical operation combines two numbers(operands) with either addition or subtraction between them and Visual Basic 2010 was used for the implementation. II. LITERATURE REVIEW CAPTCHA as a program can generate and grade tests that most humans can pass but computer programmed robots should not pass [15]. Such a program can be used to differentiate humans from computers. In general, CAPTCHA methods can be divided into five groups: Text-based CAPTCHAs, Image-based CAPTCHAs, Audio-based CAPTCHAs, Motion-based CAPTCHAs, and Hybrid CAPTCHAs [3]. A text-based CAPTCHA is a distorted image of a sequence of characters on which different types of degradations, background clutters and color mixtures are applied to make it more challenging for attackers. Text-based CAPTCHAs is introduced in six sub-groups [10] a) CAPTCHAS with “English Words” as their CAPTCHA text: i. Gimpy: Gimpy is one of the most famous CAPTCHAs which are primarily based on distorted text. Gimpy picks seven words from a dictionary; then renders a distorted image containing those words. It finally presents them to its users and asks them to type three words of the image to gain entry to the service [12]. The sample is presented in Figure 1. Figure 1: Gimpy CAPTCHA [12] ii. EZ-Gimpy: In this CAPTCHA, a word is chosen from a dictionary. In the next step, the word is rendered to an image using various fonts and different types of distortions such as black or white lines, background grids and gradients, blurring and pixel noise are added. Then, the user is asked to type the word.[16]. The sample picture is depicted in Figure 2.