Recaptcha just like captcha except that instead of entering random letters and numbers, you enter two words.

A new security measure for online purchases is also working to expand digitzed literature.

If you've ever bought or registered for anything online, you've probably seen a feature called "captcha," a series of letters and numbers that must entered to complete your purchase.

Because computers cannot read it and people can, captcha helps confirm you are an actual human and not software,
helping to prevent situations like scalpers using programs to login to Ticketmaster, buy up all the tickets, and sell them for an astronomical markup.

Carnegie Mellon University Professor Luis von Ahn, creator of captcha, said that after learning that 200 million captchas are typed each day, he decided it was time to make better use of the system.

		WATCH THE VIDEO
	REcaptcha NY1's Adam Balkin has more on how REcaptcha is helping to digitize every copy of the New York Times.

So he created REcaptcha,a program that not only allows people to gain entry to a site, but also to help digitize books.

It is just like captcha except that instead of entering random letters and numbers, you enter two words.

"You start from a scanned book or newspaper or something, a scanned image," von Ahn said. "Then you take all the words the computer can't recognize, and then the system pairs a word it couldn't recognize with one it already knows the answer to somehow, and then it gives them to humans and it doesn't tell them which is which and tells them to type both words."

"If the humans type correctly the one the system already knew, then the system gets some confidence it's actually a human, and gets some confidence they typed the other word correctly," von Ahn said.

To increase its confidence, the computer spits out that same word to several other people.

Von Ahn said that while it sounds like typing two words will take more time, because the two words are familiar to us, they're actually easier to type than random ones.

	REcaptcha was acquired by Google in September.

"Most people just don't notice because it doesn't take any longer to type two words than a random string," von Ahn
said.

REcaptcha was acquired by Google in September.

Currently it is being used primarily to help digitize every single New York Times.

Developers say it's on pace to complete that project within about a year.