At 11:06 AM -0800 11/22/01, John Young wrote:
Time Magazine, November 26, 2001:
This is a fascinating idea, but problematic. The simplest approach is easy to spoof. Let's say that you encrypt the data with the GPS coordinates X. The software takes GPS coordinates from a GPS receiver and tries to decrypt the data using these coordinates. Only someone at the right place would be able to figure it out. Naturally, this could be spoofed by replacing the GPS receiver with one that spits out the right coordinates. A better system might rely upon the signals from the satellites themselves. The signals let the GPS receiver measure the time the signal took to travel from the satellite to the receiver. Knowing the distance from three or more satellites makes it possible to triangulate and come up with the real location. A more sophisticated system would encrypt the data with these signals themselves. It might take the data coming from satellites 1,2 and 3 at one particular instant. Only a person in the right location would see the right values at that particular instant. But I think this could be spoofed by time shifting the signals using a TIVO-like mechanism. If you're not in the right location you could pretend to be in another. Maybe they have a more complicated mechanism. Or maybe this is just FUD. -Peter
Denning's pioneering a new field she calls geo-encryption. Working with industry, Denning has developed a way to keep information undecipherable until it reaches its location, as determined by GPS satellites. Move studios, for example, have been afraid to release films digitally for the same reasons record companies hate Napster: once loose on the Internet, there's little to stop someone from posting the latest blockbuster DVD on the Web for all to see and download. With Denning's system, however, only subscribers in specified locations -- such as movie theaters -- would be able to unscramble the data. The technology works as well for national security as it does for Harry Potter. Coded messages that the State Department sends to its embassies, for example, could only be deciphered in the embassy buildings themselves, greatly reducing the risk of interception.
For now, Denning says, terrorists "may want to bring down the power grid or the finance system, but it's still easier to blow up a building." If she's right, it's due in large part to her.