The Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) has been widely used as a technique that will allow a machine to distinguish between input from a human and that of another machine. The security of current CAPTCHA methods is not sufficient to protect against advanced modern malware. This paper focuses on applying gamification, the use of game elements in ...

The effectiveness of CAPTCHA challenges largely depends on being simultaneously easier to solve for humans and harder to solve for bots. In this work we argue that it is possible to enhance the effectiveness of audio CAPTCHA challenges by adapting the challenge to the users’ characteristics. We propose a method for achieving this adaptation while protecting users’ privacy. Moreover, our approac...

Smartphones play an important role in the information-communication society and accesses from smartphones to the Internet services increase more and more with the advent of cloud computing. Smartphones have comparatively small displays and it is possible for users to input data through touchscreens. The techniques such as a CAPTCHA (Completely Automated Public Turing test to tell Computers and ...

CAPTCHA stands for Completely Automated Public Turing Test to Tell Computer and Human Apart. It is the test that human can pass easily but computer cannot. For example, humans can read distorted text, but current computer programs cannot. For many years, CAPTCHAs have proven very useful for many reputable, Web-based email and application service providers, including social networking sites and ...

Information and computer security is supported by passwords. Password is the principal part of authentication process. The traditional authentication method is to use text-based password which is also called alphanumeric password. But it has significant drawbacks. So to overcome vulnerabilities of this traditional password scheme a graphical password scheme is developed. But major drawback of g...

-We are in the era of internet and depend on it for every necessary requirement. It is the tendency of the some human to have destructive approach rather than having constructive approach. Among the abuse and misuse of internet, the distributed denial of service attack (DDOS) is the most hectic one. People have carried out various method of mitigation using the CAPTCHA (Completely Automated Pub...

Recently, with the spread of online services involving websites, attackers have opportunity to expose these malicious actions. To protect services, A Completely Automated Public Turing Test Tell Computers and Humans Apart (CAPTCHA) is a proposed technique. Since many Arabic countries developed their in Arabic, text-based CAPTCHA has been introduced improve usability for users. Moreover, there e...

Many security primitives are based on hard mathematical problems. Using hard AI problems for security is emerging as an exciting new paradigm, but has been under-explored. In this paper, we present a new security primitive based on hard AI problems, namely, a novel family of graph-ical password systems built on top of Captcha technology, which we call Captcha as graphical passwords (CaRP). CaRP...

As one of the advanced Completely Automated Public Turing tests to tell Computers and Humans Apart (CAPTCHAs), the CAPTCHA using mental rotation has been proposed. Mental rotation is an advanced human-cognitiveprocessing ability to rotate mental representations of “one” single 2D/3D object. However, as have already been reported, the mental rotation CAPTCHA can be overcome by pattern matching a...