Web Security Words Help Digitize Old Books

On “All Things Considered”

People who use the Internet to talk to friends, set up free e-mail accounts or buy concert tickets are often unknowingly helping to digitize vast libraries of old books and newspapers.

That’s because more than 40,000 Web sites — including popular ones such as Ticketmaster, Facebook and Craigslist — are using a new kind of security program called reCAPTCHA.

It’s the brainchild of Luis von Ahn, a computer scientist at Carnegie Mellon University in Pittsburgh, who helped develop another commonly used Web security system. That one, called CAPTCHA, will allow people to access a Web site only if they prove they are human — and not a spammer’s computer — by typing in a sequence of letters or numbers that appear on the screen in a distorted or garbled image.

Listen to full piece here.