GPS Hacking, Part 1

Looking through the drops.wooyun.org website, it appears that every image posted is watermarked. It seems to be a blogging platform targeted towards hackers, with lots of authors represented. I imagine that the watermarking is an automated process applied to every image uploaded to the platform.

Of course, the author should have given attribution.

Definitely illegal.

The FCC rules for Amateur radio which is defined in Part 97 clearly states that an amateur may not disrupt radio location services. The frequency for the GPS Signals, high UHF is not close to any privileges available, amateur operators included. In short, don't do this unless you're testing / putting out very low power. Better yet, get an RF enclosure.

Here is a graphic of the spectrum available in the US: https://www.ntia.doc.gov/files/ntia/publications/2003-alloch...

You can get a Part 5 experimental license, although a likely condition of getting such a license would be taking steps to ensure that your work doesn't interfere with devices outside of a small designated test area. Alternatively, you can do all the GPS experimentation you want inside of a shielded chamber without asking permission from anyone.

The FCC would have absolutely no problem at all throwing around at least 5-digit fines for doing these things.

Beyond that, though, GPS is still considered military technology. The state department could very well come after you for exporting military tech were you to even make a blog post about it while based-in or having any ties to the US. They really don't fuck around with this stuff.

I got to play with a real GPS simulator a few years back for a school project (visiting the local defense contractor to verify some equipment) the narrow part of which was testing an unlocked (height and velocity restrictions disabled) GPS receiver as it would work in LEO.

Yes, very illegal. Which makes me remember to ask: how did Todd Humphreys get permission to transmit a spoofed signal [1] in the middle of a thriving metropolis, within a couple of miles of an airport?

[1]http://alcalde.texasexes.org/2012/06/ut-demo-reveals-drones-...

Yes.

Only against imperfect spoofing.

A GPS receiver in Los Angeles sees the same set of signals as a receiver in San Francisco - just the relative arrival times of the signals are different by, at most, a single-digit number of milliseconds.

So an attacker just needs to do a replay attack, and all the almanac stuff checks out fine because it's a perfect replica of the authentic signal.

Most phones also have a GLONASS receiver, which is Russia's GNSS.

I'm pretty sure the self-driving system wouldn't rely on GPS much, especially considering how inaccurate GPS can be (and that's when you can actually get a signal).