In the past week, I've had three clients ask me why they have to decrypt a set of squiggly letters and/or numbers almost every time they fill out an online form.
The simple answer: so the website knows you're human.
It's called a CAPTCHA
(for Completely Automated Turing Test to Tell Computers and Humans Apart). A CAPTCHA is a program that can generate and grade tests that humans can pass but current computer programs cannot. For example, humans can read distorted text, but current computer programs cannot.
CAPTCHAs are used by millions of websites to prevent abuse from "bots," or automated programs written to generate spam. Bots can't read distorted letters, so they can't get past the CAPTCHA feature.
If you don't already have a CAPTCHA on your online form, you should add one. It's pretty straightforward, but you'll probably need help from a web programmer. They're great for preventing comment spam in blogs, giving more validity to online polls, and protecting your free registration processes (who wants a computer overloading your system with bogus account setups). Even for simple contact forms or email-this-page features, they prevent the headaches of spurious submissions.
But what's even more amazing is a new program called reCAPTCHA. Instead of having you type random characters as CAPTCHA does, when you use reCAPTCHA, you're actually unknowingly helping to digitize vast libraries of old books and newspapers.
It's definitely one of those wish-I-had-thought-of-that-first ideas. I heard about it on NPR this week; check out the article and podcast on their website for the full details
But in short, reCAPTCHA is the brainchild of Luis von Ahn, a Carnegie Mellon University computer scientist who helped develop the original CAPTCHA. He quickly realized how much time people were wasting typing in those twisted letters and thought that time could be put to better use, perhaps deciphering words that really
needed to be deciphered. Enter libraries and newspapers trying to digitize their collections.
Ahn paired with The New York Times
, which is digitizing newspaper back to 1851, and a nonprofit called the Internet Archive, which is digitizing thousands of books. And in the past year, he says web users using reCAPTCHA have transcribed enough text to fill up more than 17,600 books!
Bravo Ahn! Finding a way to make to make websites more secure while digitizing old print resources at the same time. Brilliant, I say. ...And reCAPTCHA is a free service. Check out their site at www.recaptcha.net.