A non OCR approach for math CAPTCHA design based on Boolean algebra using digital gates to enhance web security

CAPTCHA is widely research field become a ubiquitous defense to protect open web resources from automated access. The objective of CAPTCHA is to give genuine services to every user by minimize automated approaches. An efficient CAPTCHA must be not only human friendly, but also robust enough to resist to machine attacks for pass CAPTCHA test. Many CAPTCHAs have been proposed in literature like text-graphical based, video based, mathematical or questions based. The miscreants attempt to effectively bypass these CAPTCHA test by use optical recognition or machine learning techniques. The design and implementation of CAPTCHA lie in the domain of artificial intelligence. We aim to design a CAPTCHA, which will effectively use by modern digitize world and turn to reduce the optical recognition and other automated attacks. In this paper, for better security issues, a non OCR CAPTCHA design called digital CAPTCHA based on Mathematical Boolean algebra by use digital logic gates. The different logic gates design which depict shapes like (AND, OR, NOT, NAND, NOR). Each gate executes multiple answers based on Boolean algebra by use Boolean laws. For prove human, user recognize shapes of logic gates and choose a correct answer from multiple answers. The experimental results analyze by multiple technical and non technical users with different age groups. The resulting values show that our proposed system has high probability and security and resists the visual attacks with existing math CAPTCHAs.