What is CAPTCHA?
CAPTCHA is a challenge-response test that protects websites from being attacked by spam bots or Web robots. The test is designed in such a way only human can pass. For example, I use a CAPTCHA technique in my Contact Form on this blog by asking image verification. The image shows distorted text which is verified when user enters text in text box.
Who needs CAPTCHA?
- A blogger – To prevent comment spam.
- A website requiring registration – To stop spammers from creating thousands of accounts.
- A Webmail (Such as Gmail or Yahoomail) – To stop spammers from creating free email accounts.
- An email user – To accept emails from humans only.
Will this totally stop spam?
Like most other things, CAPTCHA is also not 100% foolproof. Because CAPTCHA became so popular, Spammers have been devoting great amount of time and efforts to break it. Spammers have been trying hard to create a program to collect all the images and then run another program to feed them one by one.
