What Is CAPTCHA?
CAPTCHA is not a word itself; it’s an abbreviation which stands for Completely Automated Public Turing-test to tell Computers and Humans Apart. This full form well defines the purpose of CAPTCHA. Actually CAPTCHA is used as a simple puzzle hurdle, which restricts various automated programs to sign-up E-mail accounts, cracking passwords, spam sending, privacy violation etc. This CAPTCHA actually challenges a particular automated program, which is trying to access some private zone. So, CAPTCHA helps in preventing access of personal mail accounts by some un-authorized automated spamming programs.
CAPTCHA test
This challenge of CAPTCHA is not a complicated problem. Actually CAPTCHA is simply some visual test or some simple puzzle. Any mentally sound human can crack this challenge very easily, but an automated program will not be able to crack the challenge and hence it will not be able to gain access. So this CAPTCHA basically distinguishes a human and an automated program and it restricts automated programs to do violation of some private area. The CAPTCHA tests include some codes in form of some images, letters, alphabets and numbers that are intersected or overlapped over each other. And some body who wants to gain the access will need to read the code and rewrite it in specified pattern. These codes are easy to understand and rewrite for any human being. One example of CAPTCHA is “gimpy”. Gimpy select random words from some dictionary and then it create 7 puzzles by placing the chosen words in a particular pattern. Pix is also a type of CAPTCHA, it uses pictures in order to create some puzzle. This system uses around 6 pictures as a puzzle. All these pictures will have relation with some common topic and a user will be supposed to identify that topic or issue.
Problems with CAPTCHA
Actually CAPTCHA is facing a few limitations. A person having sight problem will not be able to respond to CAPTCHA problems efficiently. Moreover CAPTCHA is not safe against spammers; they can take an advantage of simple puzzles to crack spam and viruses. Even spammers can also develop such programs which will be able to understand the patterns of puzzles written by a particular system of CAPTCHA. And then they will be able to crack hurdle of CAPTCHA. Moreover, some CAPTCHA images are very difficult to interpret for humans also. This complex system can turn off some important clients or users of some CAPTCHA protected access point.
Advantages of CAPTCHA
In spite of above mentioned problems CAPTCHA is still working as an important internet rectifier system to distinguish genuine users and automated programs. It is still working fairly in many usual settings. It avoids accessing of E-mails by thousands of spammers every day. So, CAPTCHA can be classified as a very important tool, but it still needs improvement. And this system is needed to be updated time to time, which will make it able to fight with new tricks of spammers. Keeping good aspects of CAPTCHA in mind, various computer experts are working on this technology to make it much more prominent to fight against automated programs.
