I own that file. I can prove it.

Short Form


Scenario: You're the lead in a team software project for school. One week from the deadline, you get a call from the Dean. Somebody's taken your project requirements document and uploaded it to rent-a-l33t-coder.com. Your fingerprints are all over the doc. You're accused of cheating and threatened with expulsion from school. What do you do?


Electronic documents are frustratingly idempotent. They’re easy to duplicate. The catch is, you can’t prove who owns the rights to a particular file.

A common anti-piracy scheme is to require a unique product key, which ties your copy of the software to you. This allows a company like Microsoft to say, “sorry, that copy of our software is owned by someone else”.

But no, there’s no way you can make this kind of statement about any run-of-the-mill file.

…or can you?

Well, not strictly speaking. However, if you register your file somewhere, the rest is… well… “elementary, my dear Watson”.

Speaking experience

This is my first talk at a conference.


  • Dsc 8432 cropped

    Daniel Sauble

    Puppet Labs


    A front-end engineer at Puppet Labs in Portland, OR, Daniel has a B.S. in Computer Science from Baker College and began an M.S. in Electrical and Computer Engineering from Purdue University before dropping out to work full time at Puppet Labs in January 2012.

    Heavily vested in internships throughout school, since 2004 he’s worked at IBM, Intel, HP, Nike, and FEI. Finally, in 2011, he found his area of passion—Human-Computer Interaction—and is doing his best imitation of a sponge, working with a world-class UX team and absorbing as much knowledge as humanly possible.