Captcha

                   

WHAT IS CAPTCHA? 

         A Captcha is used in computing for verifying whether the user is human or not.

CAPTCHA is mainly used as a security check to ensure only human users can pass through. Generally, computers or bots are not capable of solving a captcha.

CAPTCHA Full form is
C-Completely
A-Automated
P-Public
T-Turing test to tell
C-Computers and
H-Humans
A-Apart

     Captcha is generated by distorting an image with text/numbers, in such a way that any OCR technology fails, and only a human eye can read and make sense.However, one can notice that captcha are getting harder as time progresses. This is because, usage of latest advanced pattern recognition and machine learning algorithms are capable of solving simpler captcha, so the latter should be in a position to defeat the former.

WHY CAPTCHA?

                    Just about any time you sign up for an online account, you have to prove that you're a human, by reading and entering some messed-up text that supposedly couldn't be decoded by a computer.

             For example, few years back Yahoo suffered from an attack where a computer bot used to create several email accounts on its own.

   A machine could use a script to instantly create a million Facebook accounts. He could cause a lot of trouble with those before Facebook shut him down. With a million fake email accounts he could send tons of spam. Using a million fake Amazon accounts he could falsely send any product to the apex of popularity or sink it to the "worst ever" category. Clearly it makes sense to limit these accounts to actual humans.

ADVANTAGES OF CAPTCHA:

• Reduces spam.
• Makes Online shopping safer.
• Protect Passwords from Brute-force attack by the Hackers.
• Makes Online polls legitimate.
• Diminishes abuse of free e-mail account services.

DISADVANTAGES OF CAPTCHA:

• Sometimes very difficult to read.
• Time consuming.
• Not compatible for users with disabilities.

FUTURE OF CAPTCHA'S:

One is getting frustrated by typing these captcha's. Google plans to make CAPTCHA frustrations a thing of the past with its new system, Invisible  Recaptcha.

         reCAPTCHA is a free service that protects your website from spam and abuse. RECAPTCHA uses an advanced risk analysis engine..