Denning's Geo-crypto

[Eugene Leitl]

On Thu, 22 Nov 2001, Eugene Leitl wrote:

> Given that a GPS receiver gets ephemeris data, almanach data and
> pseudorandom code from each currently visible sat it has probably to do
> with the latter. Consider S/A (which may or may not be switched off now, I
> haven't checked): if you've got a secret part of the key you can refine
> your position despite deliberate degradation (selective availability) than
> the party without the key.

Forgot the URL: http://www.csr.utexas.edu/texas_pwv/midterm/gabor/gps.html

The PRN is a tapped feedback shift register.