Localized CAPTCHA for illiterate people
Nowadays, many daily human activities such as education, commerce, talks, etc. are carried out through the Internet. In cases such as the registering in Websites, some hackers write programs to make automatic false enrolments which waste the resources of the Website while this may even stop the entire Website from working. Therefore, it is necessary to tell apart human users from computer programs which is known as CAPTCHA (completely automated public turing test to tell computers and human apart). CAPTCHA methods are mainly based on the weak points of OCR (optical character recognition) systems while using them are undesirable to human users. So the non-OCR-based CAPTCHA methods are proposed. In these systems users do not need to type anything. In this paper a new non-OCR-based CAPTCHA method is introduced. In this method some objects are chosen randomly and the pictures about these topics are downloaded from Internet. These pictures are shown on the screen. Then the user is said to choose a specific object. Instead of writing the question, it is said. Therefore people who are illiterate and have difficulty in reading, can easily pass the test. Also the question is said in the native Website language (e.g. Persian), therefore the user should not know English language. If the user chooses the right image we can guess that the user is a human and not a computer software. The main advantage of this method is its simplicity because the user does not have to read or type anything. This project has been implemented by PHP programming language.