Important information on the "Ninja Party" mode of your DEFCON 18 badge.
(Hardware hackers reverse engineering the algorithm want to read this)
This is not a hardware hacking contest!
Q: What is the "Ninja Party" mode on my DEFCON 18 badge?
A: The "Ninja Party" mode is a way to "unlock" an invitation to the Ninja Party if you are given a valid unlock code. Valid unlock codes are included with every Ninja Badge. The idea is that the person with the Ninja Badge can give the unlock code to a friend, and that person can unlock their DEFCON badge, then come with them to the Ninja Party. (Your badge can be unlocked with INVALID codes by reverse-engineering the algorithm, but they most likely won't let you into the event. Keep reading.)
Q: My badge says "locked." How do I unlock it?
A: Valid unlock codes are included with every Ninja Badge. It is the "plus one" so Ninja badgeholders can bring a friend. All you need to do is have your friend with a Ninja Badge give you their code. Use this code to unlock your DEFCON badge. On the Ninja Party screen, press the bottom button on your DEFCON badge, and enter the tumbler sequence shown on the card. This will unlock your DEFCON badge.
Q: Can I just reverse engineer the algorithm on the badge to unlock it?
A: Yes and no. Here's what will happen. The algorithm has TONS of codes that will actually cause the badge to read "Unlocked". HOWEVER, only a fraction of these codes are actually valid for entry. We have a pre-selected database of valid codes representing a fraction of the total codes. At the event, your badge will be electronically read. If the code on your badge passes the algorithm but is *not* in our database, it won't work. It'll even flash a "hacked badge" message at you. :) So if you really want to try your luck with a hacked code - that's totally up to you.
Q: So this isn't a hardware hacking contest?
A: No. Think about it - the source code to generate/validate codes is simple to access. If we wanted to make a contest, we'd make something difficult. The algorithm is published on twitter. You are more than welcome to hack at the Ninja mode of the badge however you want, but that's not really what it's about. It's really about the feature being interesting and a fun way to do party invitations.
Q: Can I share my badge or my unlock code?
A: At the event, each code is scanned and logged. If an "unlocked" DEFCON badge is used more than once, it'll flash a message alerting that it's already been used. So, you probably don't want to share your code. You certainly can do whatever you want with it, but it'll only work once at the event. If people just want to make their badges say "Unlocked" - go nuts. :)
Q: Is there anything else in the Ninja Mode?
Huge thanks to Joe Grand for working closely with us on this implementation!