AT&T is $.40/minute, still very high, for larger units such as $100 purchases of minutes. --Declan On Sun, Jan 07, 2001 at 07:55:57PM -0500, 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,

__________________________________________________ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online! http://photos.yahoo.com/

-- Paul H. Merrill, MCNE, MCSE+I, CISSP PaulMerrill@ACM.Org

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,

__________________________________________________ Do You Yahoo!? Yahoo! Photos - Share your holiday photos online! http://photos.yahoo.com/

-- Paul H. Merrill, MCNE, MCSE+I, CISSP PaulMerrill@ACM.Org

Hi, I don't believe cell phones can be queried while they're off. The phone has to xmit a pulse (to hear a pulse, crank up your PC speakers, turn on your cell phone and place it within 3 inces of a speaker...you'll hear the speakers produce static at a regular interval [about every 30 seconds or so with my startac]). In an unscientific study, I've placed my cell phone, turned off, next to the speakers and not heard the familiar pulse. Also since you posed the question I ripped open my recently acquired Motorolla Timeport. Not seeing any activity in the xmit circuitry when the battery is plugged in and the power is turned off. Of course I'm having trouble putting the case back on the phone correctly but I'll figure that out later ;) phillip zakas -----Original Message----- X-Loop: openpgp.net From: Ray Dillinger [mailto:bear@sonic.net] Sent: Monday, January 08, 2001 11:10 AM To: Phillip Zakas Cc: Multiple recipients of list Subject: RE: cell phone anonymity On Mon, 8 Jan 2001, Phillip Zakas wrote:

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.

Hm. Okay. I knew there were locators in them, and had assumed that they were GPS. My mistake. Does anyone know any particulars about whether these phones can be queried for their locations while not in use?

IMHO, the real privacy issue with cell phones is the security of a conversation.

Yes indeed. Privacy is a tougher thing to achieve than anonymity, at least with cell phones. Bear

On Mon, Jan 08, 2001 at 02:14:43PM -0500, Ray Dillinger wrote:

This pretty much kiboshes the idea that they might be continuously broadcasting; I'm more concerned about the idea that there may be some signal they're passively listening for, to which they will *respond* with a pulse signalling their location.

Indeed, Motorola has done a good job building their pagers so that they'll run a long time on a relatively small battery, because they've got internal timers which shut down even the receive circuitry between transmission cycles; they wake up every so often to listen for pages, then go back to sleep - if they go outside a coverage area, the battery life drops substantially because the receive circuitry is active full-time waiting to find a familiar signal. I have no information that this technique has been used in cellphones - or will be - but it's already in consumer-grade technology that's been shipping in volume for years now. So it's certainly not difficult to build a wireless device which remains active on very low power, waiting for a signal from its Real Owner to wake up and do something. -- Greg Broiles gbroiles@netbox.com PO Box 897 Oakland CA 94604

On Mon, 8 Jan 2001, Phillip H. Zakas wrote:

I don't believe cell phones can be queried while they're off. The phone has to xmit a pulse

Quite right. In addition to this, the data used to triangulate a phone usually originates in the phone itself - GSM phones periodically transmit field strength measurements to the base station of all the cells they hear. This is the basis of normal triangulation, as most GSM networks do not have a triangulation capability built in. Sampo Syreeni , aka decoy, student/math/Helsinki university

On Mon, Jan 08, 2001 at 03:10:55AM -0500, Phillip Zakas wrote:

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

For now; future trends include GPS. See an article I wrote below. -Declan http://www.wired.com/news/politics/0,1283,40623,00.html Qualcomm, for instance, said that its gpsONE technology shifts the choice to whomever is holding the handset. The user has three choices: a default of always on or always off, the option of deciding every time the device is used, or choosing which applications will reveal the information. The company argues that providing its customers with that flexibility will give them even more options than they enjoy with landline phones, which often reveal the subscription address of the person paying for the service. The gpsONE technology, which uses both GPS technology and base station triangulation, can locate a user within a diameter of 5 to 15 meters outdoors, and 30 to 60 meters indoors.

On Mon, Jan 08, 2001 at 12:59:26AM -0500, Ray Dillinger wrote: | 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 There are a couple of location technologies in use. GPS is not (as far as I know) actually deployed. Much more common is triangulation, generally without the handset's cooperation. New phones will have tools in them to help with the triangulation process. All of these will work if the phone is switched on. GSM phones talk to the network regularly for call-routing optimization purposes. The E911 requirements in the US include a requirement for covert "authorized" querying of the phone's location. Doubtless, this message will be strongly authenticated by a police-only PKI, and your phone will log it for later audit purposes. You might want to look at 3GPP TS 22.071 or 23.171, which can be found off of http://www.3gpp.org/3G_Specs/3G_Specs.htm Also, I'll point out that it should be possible to combine the RF fingerprinting techniques being used to combat cloning with triangulation techniques, and track phones regardless of what crypto they're using. You are, after all, carrying around a broadcasting radio. Adam -- "It is seldom that liberty of any kind is lost all at once." -Hume

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

* Ray Dillinger [20010108 21:40]: [..]

... This monumental stupidity was a feature of the circus of fools around me for many years, and is still where my mind goes by reflex action whenever I hear about electricity supply difficulties, power costs and escalating home insurance prices -- however irrelevant it may be to the situation in California.

Don't worry -- electricity supply difficulties are a problem here in sunny-but-raining-today California too. In fact, it's a *big* PITA at the moment here. Super big.

California, it seems, has its own set of completely different acts in the circus of fools, and I'm still learning them....

They are not completely different. Sure, there are some unique ones but there is plenty of overlap. :) -jr ---- Josh Richards [JTR38/JR539-ARIN] Geek Research LLC - URL:http://www.geekresearch.com/ IP Network Engineering and Consulting