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 ...

-------------------------------------------------------------ABSTRACT-------------------------------------------------------A novel technique of Captcha is regenerated by using composite images that are generated in the given data base. Captcha is a type of challenge response test used in computing to determine whether or not the user is human. Captcha are used to prevent bots or automated prog...

Since their inception, captchas have been widely used for preventing fraudsters from performing illicit actions. Nevertheless, economic incentives have resulted in an arms race, where fraudsters develop automated solvers and, in turn, captcha services tweak their design to break the solvers. Recent work, however, presented a generic attack that can be applied to any text-based captcha scheme. F...

The research presented in this thesis aims to extend the capabilities of human interaction proofs in order to improve security in web applications and services. The research focuses on developing a more robust and efficient Completely Automated Public Turing test to tell Computers and Human Apart (CAPTCHA) to increase the gap between human recognition and machine recognition. Two main novel app...

Over the last decade, it has become well-established that a captcha’s ability to withstand automated solving lies in the difficulty of segmenting the image into individual characters. The standard approach to solving captchas automatically has been a sequential process wherein a segmentation algorithm splits the image into segments that contain individual characters, followed by a character rec...

The internet and web security are integral aspects of our daily lives. Many commercial firms provide clients with services. For access, it is assumed that only the genuine user, who a human, will register. Yet automated hacking programs can also do registrations fake data consume lot bandwidth, slowing down or occasionally even shutting websites, leading to Distributed denial-of-service (DDOS) ...

A Completely Automated Public Turing Test to Tell Computers and Humans Apart (CAPTCHA) is a simple test that used on websites differentiate between human users automated attacks indulge in spamming other fraudulent activities. text-based CAPTCHA the most popular security technique by many Internet, such as Microsoft, Google eBay, secure their sites from attacks. By design, however, unable legit...