Tuesday, November 1, 2011


I started experimenting with animated captchas with David Jeske back in mid-2007 while at Google. Our hypothesis was based on two opportunities. First, because of how good humans are at understanding visual information, it may be possible to make 3d motion captchas which are both more mathematically challenging to break and easier for human users to answer. Second, a motion based captcha that takes time to view would increas the cost of 'human captcha farms', where users are paid to answer captchas. As sound as we felt our hypothesis was, at the time we were unable to come up with something better than existing static images. After multiple weeks of 20% time, the effort was shelved.

Fast forward to mid 2011. Current captcha techniques seem to be losing the battle between accessibility and protection. Users can attest that captchas are becoming so distorted it's often hard for legitimate users to answer them, yet advanced cracking techniques and captcha farms are continuing to compromise them. David and I still believed in our original hypothesis, and I wanted to take another shot at 3d animated captchas.

For us, the process of creating a better captcha is intertwined with breaking captchas. Each iteration, and our attempts to defeat our own ideas brings us closer to something possibly workable.

Our current prototypes are still very much a work in progesss, and you can help evaluate and refine the ideas! Visit the test site (www.vappic.com) to participate in the usability study for accuracy and timing. Once I enough statistics, I'll release the data. If any hard core engineers are interested in trying to crack the designs, please let me know.

1 comment:

  1. Checkout Kool Captcha!