Just a minor correction to the below posting: cell phone locations are NOT calculated using GPS. They're triangulated via the three nearest cell sites reading the cell phone signal. Accuracy is much lower than with GPS, but good enough for cops to, say, find a stranded motorist on a highway. I believe resolution is somewhere around 40 meters in densely populated areas (where there are many cell phone towers). This resolution figure varies from region to region. GPS, as you know, relies on the satellite GPS system which requires special electronics and antenna systems that neither US-based (cdma, tdma, etc.) nor Europe-based (GSM) nor Japan based cell phone systems incorporate into cell phones. The only system which MAY have included GPS (but I don't think they included it though they could have) was IRIDIUM, which is now used by the US Navy and US Special Forces units for remote communications...yes IRIDIUM is still alive and kicking. Turns out their satellite-to-satellite communication, which uses direct laser communication, is pretty secure. :) IMHO, the real privacy issue with cell phones is the security of a conversation. Digital cell phones use padded encryption keys which effectively dummy down overall encryption. If you cryptanalyze a transmission you'll find a nice, consistent pad of zeros in every key (how thoughtful to make the padding so consistent!) phillip zakas -----Original Message----- X-Loop: openpgp.net From: owner-cypherpunks@Algebra.COM [mailto:owner-cypherpunks@Algebra.COM]On Behalf Of Ray Dillinger Sent: Monday, January 08, 2001 12:59 AM To: Multiple recipients of list Subject: Re: cell phone anonymity 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 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. (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). 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. Bear On Sun, 7 Jan 2001, Paul H. Merrill wrote:
But, the rates on the prepaid services are exorbitant, almost a dollar a minute for the smaller recharges and they never do get good. As always, you don't get more than you pay for.
PHM
Andrew Jenks wrote:
In the US they are now selling prepaid phones in electronics stores, computer stores, and -- my favorite -- some Blockbuster movie rental locations. You go in, pick up a box, pay cash at the register, and
you're
done. No information is required at the time of purchase. Refills available from various retailers depending upon your service company. Again, you walk in, pick one up, pay cash, and leave.
-----Original Message----- X-Loop: openpgp.net From: montag montag [mailto:cels451@yahoo.com] Sent: Sunday, January 07, 2001 10:07 AM To: cypherpunks@toad.com Subject: cell phone anonymity
Please post the actual experiences about obtaining a pre-paid cell phone (aka "mobile" in the less developed world) without revealing any (correct) identifying info, such as address, telephone no, name, etc.
I know that it can be done in Canada. Unsure about US, UK and the rest of europe.
regards,
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-- Paul H. Merrill, MCNE, MCSE+I, CISSP PaulMerrill@ACM.Org