To distinguish between human user and computer program to enhance security, a popular test called CAPTCHA is used on Web. CAPTCHA has an important role in preventing Denial Of Service (DOS) attacks in computer networks. There are many different types of CAPTCHA in different languages. Due to the expansion of Persian-language and documents on internet, creating a suitable Persian CAPTCHA seems t...

The massive and automated access to Web resources through robots has made it essential for Web service providers to make some conclusion about whether the "user" is a human or a robot. A Human Interaction Proof (HIP) like Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) offers a way to make such a distinction. CAPTCHA is a reverse Turing test used by Web serv...

As protection of web applications are getting more and more important every day, CAPTCHAs are facing booming attention both by users and designers. Nowadays, it is well accepted that using visual concepts enhance security and usability of CAPTCHAs. There exist few major different ideas for designing image CAPTCHAs. Some methods apply a set of modifications such as rotations to the original imag...

Captcha is a popular real user detection or autobot/robot rejection technique used in websites for Desktops. Captcha is also in use in some of the mobile websites. Captcha are difficult to read on the smartphone and portable computer screens. Users stuck in zooming in/zooming out while reading and filling the captcha and other required fields. Old aged users feel it more difficult to view and t...

Phishing is an attempt by an individual or a group to thieve personal confidential information such as passwords, credit card information etc from unsuspecting victims for identity theft, financial gain and other fraudulent activities. In this paper we have proposed a new approach named as "A Novel Antiphishing framework based on visual cryptography" to solve the problem of phishing. Here an im...

Evolution in the world of internet has given rise to several online attacks and the most common attack is phishing. Victims are tricked into providing such information by a combination of spoofing techniques and social engineering. Phishing is an attempt by an individual or a group to acquire sensitive information such as usernames, passwords, and credit card details from unsuspecting victims. ...

Phishing is an attempt by an individual or a group to get personal confidential information such as passwords, credit card information from unsuspecting victims for identity theft, financial gain and other fraudulent activities. Fake websites which appear very similar to the original ones are being hosted to achieve this. In this paper we have proposed a new approach named as "Countering Phishi...

CAPTCHA is standard for providing security for web services. It mainly used to avoid Denial-Of –Service attack. CAPTCHA Completely Automated Public Turing Test to Tell Computers and Humans Apart or it is designed to distinguish automatic bots and human. Many different CAPTCHA were introduced and it is in use. All the CAPTCHA have some disadvantage. Textbased CAPTCHA can be easily identified by ...

CAPTCHA is a technology which has its base in a test called the Turing Test. Alan Turing, proposed this test as a way to examine whether or not machines can think or appear to think like humans. The main purpose of a CAPTCHA is to block form submissions from spam botsthat is automated scripts. Various types of CAPTCHAs are used, which mostly requires users to enter the strings of characters tha...

In this paper, we propose a novel image-based completely automated public turing test to tell computers and humans apart (CAPTCHA) that relies on detecting human faces to provide an additional layer of security in web-based services. Face images were selected from the CMU face database and subjected to different types of distortions at different intensity levels to make the automatic face detec...