Email Print Share

"Ink Blocks" -- The Discovery Files

The Discovery Files
Audio Play Audio
The Discovery Files podcast is available through iTunes or you can add the RSS feed to your podcast receiver. You can also access the series via AudioNow® by calling 641-552-8180 on any telephone.

Computer scientists at Carnegie Mellon University have developed a password system that incorporates inkblots to provide an extra measure of protection when lists of passwords get stolen from websites.

Credit: NSF/Karson Productions

Audio Transcript:


I'm Bob Karson with the discovery files--new advances in science and engineering from the National Science Foundation.

You know those strange-looking scrambled security words that appear on some sites to distinguish between you, a human, and an automated computer attack? That technology is called 'CAPCHA' developed by computer scientists at Carnegie Mellon University. Now, from the same team comes another system that provides an extra measure of security for sensitive information such as bank accounts and medical records, especially when lists of passwords have been stolen from websites. This one's called, 'gotcha'--generating pan optic turing tests to tell computers and humans apart.

The gotcha system works with what appear to be inkblot pictures. When you go to register a password, several inkblot "puzzles" come up. You make up a short description of what each image looks like: Things like "happy guy licking a lollipop" or "lady in poofy dress." Those descriptions are stored with your password, so you don't have to remember them when you sign in. All you need do is match the descriptions with the right inkblots--a feat an invading rogue automated computer cannot do on its own. When a computer constantly needs humans to help solve puzzles, it can no longer execute automated brute force attacks that try millions of combinations every second.

The developers have posted a challenge online inviting other security researchers to try and crack their system.

Some smart inking.

"The discovery files" covers projects funded by the government's National Science Foundation. Federally sponsored research--brought to you, by you! Learn more at or on our podcast.

General Restrictions:
Images and other media in the National Science Foundation Multimedia Gallery are available for use in print and electronic material by NSF employees, members of the media, university staff, teachers and the general public. All media in the gallery are intended for personal, educational and nonprofit/non-commercial use only.

Images credited to the National Science Foundation, a federal agency, are in the public domain. The images were created by employees of the United States Government as part of their official duties or prepared by contractors as "works for hire" for NSF. You may freely use NSF-credited images and, at your discretion, credit NSF with a "Courtesy: National Science Foundation" notation. Additional information about general usage can be found in Conditions.

MP3 icon
NSF podcasts are in mp3 format for easy download to desktop and laptops, as well as mobile devices capable of playing them.