Big thanks to Hacker News for helping us win the DARPA Shredder Challenge. That's where some of our team heard about the challenge in the first place and that's where we found out about the yellow dot patterns that gave us a huge advantage over the competition that didn't read Hacker News. :P

The following caught my eye:

Then he happened on an article about a little-known government project: The Secret Service has been working with manufacturers of color laser printers to place tiny, imperceptible yellow dots on printed pages so that the government can track the machine that produced them. Good put the puzzle under a blue-light filter and saw the dots.

That's a great hack! Kudos to the team.

Where do you think I found out about the yellow dots? I was stuck on puzzle four and procrastinating by reading hacker news. Just in time, there was an article here about the yellow dots. I looked at the shredded pieces and they were there in a nice pattern. Hacker news FTW!

I have known about these yellow dots for years, but it never occurred to me that DARPA would have used color printers for this competition.

I need to fire up those 'orthogonal thinking' neurons!

This is amazingly clever. Congratulations on the win! Would you consider posting something about the process you took?

We have been meaning to do that but have been distracted by real life. Hopefully we'll get it together soon. I'll post a link on HN when we do.

I did the first two puzzles. I skipped to the fourth when I saw different colored inks on a hunch that the names were in different colors. I wrote an algorithm to pick out the different colors, but got too burnt out to finish. I felt bad when I saw my hunch was right. Well done using the yellow dots, that was quite a novel approach. Congrats on your win.

Very clever. Kudos on shipping a new rev of Word Lens, too.

That's an absolutely brilliant hack. I was playing with those challenges a bit, I've read about those yellow dots multiple times, but it not once occurred to me to use them. Well done.

DARPA shot themselves in the foot here, right? This fourth challenge was a handwritten, unlined letter, and would have been vastly more difficult to solve were it not for this unintended pattern.

A twist solution that stumped basically everyone until a single team solved it using a pretty creative solution... sounds perfect for such a competition. What makes you think they didn't do it on purpose?

A handwritten letter that's been printed on a colour printer, it appears rather incongruous. It seems to me DARPA hoped for a novel (or cheap, or whatever) way of piecing together a handwritten letter, but got something else instead. Still, all kudos to the winner of course. Even with the dots it's quite an accomplishment.

More lateral thinking puzzle, less deployable intelligence expertise. A public coming out about this channel?

This is similar to the optional programming question at ai-class.org. NLP.

"All Your Shreds Are Belong to U.S." clever name.