At 12:59 AM -0500 1/8/01, Ray Dillinger wrote:
On the larger purchases, the costs drop down to the forty-cents-a-minute range. Totally worth it if you really *need* anonymity on the phone.
Of course, anonymity is relative; these phones have built-in GPS chips for 911 calls, and these are activated from the central office, not by
Which of these phones have built-in GPS? Gonna be a real shock to Trimble, Magellan, and Garmin that the GPS units they're still selling for $100 and up are competing with cellphones given out free with new accounts! GPS is getting cheaper, and may someday appear in even inexpensive cellphones, but that day has not yet come.
a 911-sensing circuit in the handset. IOW, it is not impossible for someone with the right gear and knowhow to query the phone for its exact latitude and longitude at any moment when it's in use.
Why do you believe this to be so?
(I don't know whether it can be queried when it's switched off, nor if so whether removing the main batteries will stop it).
A backup battery is likely only usable for the local storage of temporary parameters, and probably not even that. I don't recall any mention with either my Motorola Star-Tac or my current Nokia about backup batteries. Which means that when the main battery pack is removed, the circuitry is "OFF." No power to transmit. (And forget passive sensing, as with some radio or t.v. tuning coils of old, as that required being very close to the coils to detect resonances. And no longer even applicable, what with digital tuners.)
So if you're into hard anonymity, keep it inside a faraday cage when you're not using it and don't use it from inside your own dwelling.
Faraday cages don't have to be fancy; a fruitcake tin will usually do.
Removing the battery is easier. Turning the phone off is _probably_ (I am convinced of this, but haven't studied it in detail) enough to stop any location detection, at least with the current generations of cellphones. (The very long battery life of a turned-off Nokia vs. a turned-on Nokia tells us a lot about what it could possibly be transmitting.) As for Faraday cages, there are easier options that a fruitcake tin. Reception is bad enough in mountainous areas like mine. Ray, you seem knowledgeable in some areas. But your pontifications on California basements, cellphone GPS, etc., are very "Choatean" in nature. Something you might want to look at. --Tim May -- Timothy C. May tcmay@got.net Corralitos, California Political: Co-founder Cypherpunks/crypto anarchy/Cyphernomicon Technical: physics/soft errors/Smalltalk/Squeak/agents/games/Go Personal: b.1951/UCSB/Intel '74-'86/retired/investor/motorcycles/guns