期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2020
卷号：9
期号：1
页码：12807-12813
DOI：10.15680/IJIRSET.2020.0901015
出版社：S&S Publications
摘要：In today’s digital world, security plays an important role in the field of web applications. It is required to
protect the website or user data from different kind of machine attacks. To ensure the security, CAPTCHA is a tool
through which a turing test can be performed and identify whether the user is human or a robot. CAPTCHA stands for
Completely Automated Public Turing Test to tell Computers and Human Apart. Machine based attacks can harm the
database by enrolling junk entries and an account can be hacked through brute force attack. By having these problems
on mind, there are so many CAPTCHA techniques have been introduced such as text based CAPTCHA that involves
3D text, moving text, distorted text other than text CAPTCHA there are also graphical CAPTCHA, Audio CAPTCHA
and one time password based CAPTCHA have been carried out for better security concerns. The motive of this paper is
to review the previously proposed systems that may have some bugs and complicated for human to solve in less time.
The paper also emphasizes the proposed solution or system that replaces the existing system and provides better level
of accuracy.
关键词：CAPTCHA; Artificial Problem; Turing Test; Attacks; Web Security;
