Alok Menghrajani

Previously: security engineer at Square, co-author of HackLang, put the 's' in https at Facebook. Maker of CTFs.

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A puzzle I designed for Square's 2016 CTF. I was inspired by DefCon's badge puzzles (significantly easier to solve however).

Want to try it out? Reach out to me and I might be able to mail out a spare.

Some info

  • Feel free to abuse the hardware; it's yours.
  • The board is easy to power from a wide range of sources. Don't go over ~35V. Some components might heat up a little.
  • Solving the puzzle may require using sharp or hot tools (knives, soldering iron, etc.). Handle your tools carefully.

Hazardous substances

  • The board is lead-free. It was printed thru Oshpark.
  • The components were choosen to be RoHS compliant, lead free. They were purchased on Digikey
  • I used a variety of different solder. Unfortunately, most solder contains lead. Keep out of the reach of children.


Andy, Todor, John and Matt helped me go from prototype to a finished board; answering my various questions along the way. Cedric and Chris helped solder some of these.

Bare board (v1)
Final board (v2)
We made 12 of these!