Tuesday, October 15, 2013

What is a CAPTCHA and How Does It Work

CAPTCHA, an acronym that stands for Completely Automated Public Turing Test to Tell Computers and Humans Apart is a type of test to ensure that the response is generated by a human rather than a
computer.The most common form of CAPTCHA is an image of several distorted letters.The main reason behind using captchas is that it avoids bots from causing harm to the sites by working as per
instructions.The CAPTCHA test helps identify which users are real human beings and which ones are computer programs.One interesting thing about CAPTCHA tests is that the people who design the tests aren't always upset when their tests fail. That's because for a CAPTCHA test to fail, someone has to find a way to teach a computer how to solve the test. In other words, every CAPTCHA failure is really an advance in artificial intelligence.
CAPTCHAs can prevent bots from passing the test thus ensuring security to the system.A Bot cannot be programmed to pass a captcha,since it varies randomly and its unable to predict its type.Captchas
are generally used by sites that has many traffic which the hackers usually target.Inorder for a bot to pass the captcha test,it has to be programmed with an algorithm that executes the way we humans
think which is impossible at the moment.Therefore Captcha system can control spams.

A Captcha work by generating gifs of scrambled words that can be passed only by human intelligence.There are also .mp3 type voice recordings for users who do not like captcha.


No comments:

Post a Comment