Sky Has No Limits...! So Do I....!

Hey all...! I got puzzled & Irritated as every time I browse, every site asks me to re-type a set of scrambled, crushed set of characters..! Also that was the time I was thinking on, about my next article. So, I invested my time in finding about those set of scrambled characters..! I came to know those are "CAPTCHA"s. "Oops...what's this"?.

A "Captcha"....what is that..!
A captcha is a program which generates a simple test to identify humans from computers by comparing and grading the test results. The acronym for CAPTCHA is "Completely Automated Public Turing test to tell Computers and Humans Apart". The test procedure usually has a computer (a server), which prompts the user to answer the particular question. This result is generated and compared with in the computer ( server) itself, ultimately identifying whether the user is a computer which generates auto message or a human. The questions are so simple and carefully designed so that only humans can attend to it. Computers cannot respond to it. Sometimes humans themselves fail in the test.

So By this time am sure that you must be wondering what kind of questions are asked in test...!!

Nothing big. The computer server generates a set of characters scrambled together, scratched, extended, highlighted, jumbled up with upper & lower case, usage of special characters and numbers, which only humans can reproduce. The computers cannot recognise such characters and reproduce them. But most of the humans can reproduce which signifies it is not a bot.
This is sometimes described as a "REVERSE-TURING TEST", because in this test, the humans are the targets, administered by the computer(server).
so wondering what is a "TURING TEST"..? A turing test is conducted to prove the machine is as intelligent as humnas. The test is administered by humans, targeted at machines.

Now lets undergo a "CAPTCHA"..test...
In the window shown beside, there are set of characters, which has to be reproduced and entered into the tab provided above it. Now when such a test is challenged to a computer, It cannot reproduce the characters and probably it cannot identify it as a test. But most of the humans reproduce them correct
and get recognized as humans. Recent development also has audio captcha's for those people who are partially visually impaired.









So after knowing about Captcha's and the CHALLENGE-RESPONSE tests, now it is obvious that you will wonder why such a test is required...?

captcha s are deployed at places where automated softwares degrade the quality of service of web mails like google, gmail, yahoo, hotmail etc...
captcha s are also effective when deployed in blogs, forums etc to avoid automatic postings...
as a witness recently "orkut" for even posting scraps have adopted captcha s.

So now we all know about captcha s and now whenever & where ever we see them, you will remember this blog http://krithscorner.blogspot.com , where you got the information regarding the set of scrambled characters...!