Combatting Spams

In November 1999, there was an online poll conducted to find which is the best graduate school in computer science. But students at Carnegie Mellon wrote a program that voted for around thousand times. The next day, students of MIT also wrote a program that started to vote for them.

How could anyone trust the result of such polls? How would you know if a human has voted or its a program that has voted?

The answer to this is CAPTCHA, an acronym for "Completely Automatic Public Turning Test to tell Computers and Humans Apart". Captcha, coined in 2000, determines whether the user is a human or a program. When signing up for email accounts like Yahoo!, you could have seen a small rectangular graphic containing some distorted words like "none","care","happy" etc. This is known a CAPTCHA process. A human can read these distorted text, but computer programs cannot thus preventing spam and bots from broadcasting unwanted messages to your email.

But still some bots started using Optical character recognition to identify hidden words. The captcha was fist broken by Jitendra Malik. So, to overcome this, people at Palo Alto Research center(PARC) developed something called BaffleText. The process involves printing the image, then scanning it back, thresholding it, adding noise to it and making more worse that even the OCR cannot decipher it.

The main drawback of this technique is that, it is unfriendly to visually impaired people.

For Potter Maniacs

The much hyped JK Rowling's sixth novel "The Harrypotter and the Half-blood prince" opened a few days back. Though late, I have just bought the book and have alredy started it. Its the most gripping novel I have ever read and I was hooked right from the first paragraph. The first two chapters are most thrilling and imaginative that hooks both new readers and those who are familiar with the Harry potter series.

The war against Lord Vold..oops.."He-Who-Must-Not-Be-Named" is not going well. The Death eaters are begining to join The Dark Lord and have started spreading evil among the wizarding community. This book prepares the reader for the battle with The Dark Lord, whose past is examined much more detail than the previous books in this series and it also deals with romantic relationships of various students.

The book has been a greatest hit amoung the Muggle society, thereby making it the fastest selling book in history.

People who love to be imaginative and creative would dfinitely like this series. I would recommend new readers to try out The Encyclopedia of The Harry Potter before you wish to start off with The Half-Blood Prince.