CAPTCHA is an acronym that stands for Completely Automated Public Turing Test to tell Computers and Humans Apart (CAPTCHA), it a good example of authentication system can be used determine the true identity any user. It serves as security measure prevent attack caused by web bots (automatic programs) during online transaction. come text-based or image-based depending on project programmer. The ...

Optical scan voting systems are ubiquitous. Unfortunately, optical scan technology is vulnerable to failures that can result in miscounted votes and lost confidence. While manual counts may be able to detect these failures, counting all the ballots by hand is in many situations impractical and prohibitively expensive. In this paper, we present a novel approach for examining a large set of ballo...

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 a novel family of graphical password systems built on top of Captcha technology,which we call Captcha as a graphical passwords (CaRP).. CaRP addresses a such as online guessing attacks, relay attacks, and, if combined withdual-...

Purpose In this work we argue that it is possible to address discrimination issues that naturally arise in contemporary audio CAPTCHA challenges and potentially enhance the effectiveness of audio CAPTCHA systems by adapting the challenges to the user characteristics. Design/methodology/approach We design a prototype, called PrivCAPTCHA, to offer privacy-preserving, user-centric CAPTCHA challeng...

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 ...