I'm looking for info on GPS security, specifically, its integrity /
authentication mechanisms to protect against spoofing.
This is important since many systems assume GPS is a secure source of time
and location. (My interest in this began as we are completing paper on
proactive secure clock synchronization, and figured we ought to compare
this to the approach of using GPS receivers to provide secure time.)
As recently discussed on this and other lists, the accuracy of commercially
available (civilian) GPS has recently been improved by the removal of the
Selective Availability degradation of the Coarse Acquisition (C/A) signal.
However, after (very limited) digging up some GPS papers/web sites, I
didn't find any mention of authentication/integrity/anti-spoofing
mechanisms to the C/A signal. I did find a brief mention that the (still
encrypted) P/Y signal has some anti-spoofing mechanism; but I didn't see
any details on how that is done (such details may be confidential).
I'm interested in both the C/A and the P/Y integrity mechanisms. The
anti-spoofing of the P/Y signal is, to me, more of academical interest. I
find the C/A signal integrity more interesting as it is available for
commercial use. How hard is it to spoof it? Is there any real difficulty in
protecting its integrity ? Or is it protected well?
Thanks for any help/info.
Best Regards,
Amir Herzberg
IBM Research Lab in Haifa (Tel Aviv Office)
http://www.hrl.il.ibm.com
