Wednesday, August 15, 2012


Pain in the ass!

Yes, that’s the first thing that comes to my mind when I come across a CAPTCHA. Until recently, I was completely against CAPTCHA. Maybe because I found it really difficult to identify the words or letters or numbers.

Have you ever thought why did they even bring this concept? I hadn’t too, until yesterday when my friend gave me a short (but wonderful) lecture on CAPTCHA. I always thought CAPTCHA is a word, similar to ‘WHATCHA’. CAPTCHA is the acronym for Completely Automated Public Turing test to tell Computers and Humans Apart.

Consider the ‘Comments’ section on your blog. There are two ‘fields’ there. One is a text box where you can enter your ‘comment’ and another is a ‘Publish’ button. There are only two steps involved in this process. 1. Enter comments in the textbox. 2. Hit ‘Publish’. It’s child’s play for a computer freak to program these. I mean, to open your blog, select ‘comments’ link, enter some text and hit submit. Think of it if he runs this loop a million times? A million comments for your blog. Wow! That’s something good, isn’t it? ;)

Okay. Think if he is doing this on an email registration page. A million user ID’s and passwords with no one actually using it. They can do this with any permutation and combination of alphabets and numbers ranging different lengths. So when you try to create a user id or any user id, all you see is ‘user id already exists’.

CAPTCHAs are designed to be easy for a computer to generate, but difficult for a computer to solve, so that if a correct solution is received, it can be presumed to have been entered by a human. CAPTCHAs have many applications for security which includes – preventing comment spams in blogs, protecting website registrations, online polls, and most importantly, to prevent dictionary attacks*.

So, when an automated program or a ‘bot’ tries to gain access, CAPTCHA GOTCHA!


*CAPTCHAs can also be used to prevent dictionary attacks in password systems. The idea is simple: prevent a computer from being able to iterate through the entire space of passwords by requiring it to solve a CAPTCHA after a certain number of unsuccessful logins.

PS: I found the topic interesting. Thought I will write about it here. Hope its informative.


Chocolate Lover said...

xD CAPTCHA can be really annoying sometimes!! >_<

Anoop said...

yeah.. it can b annoyin too sometimes.. but its good u know.. i mean..its for our benefit only :D

Anita Jeyan Sandeep said...

Honestly, I dint know that it was called CAPTCHA. It is a very informative post, thank you. WHen I enabled this on my blog as some random advertisements started appearing on comments section, some readers emailed me telling me to remove it, as it was a pain in their asses :D

Anoop said...

You are welcome :D I'm happy that my post helped at least one reader :)

n you can u can always 'moderate' your comments b4 it gets published. thats easier..captcha is good too..i mean its the best.. :D

Insignia said...

Well some features as these are nuisance to layman but a real necessity for their own good. :)

Anoop said...

yeah.. thats true...


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