[liberationtech] Cell phone tracking

[Bernard Tyers - ei8fdb]

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Hello Dan,

(NB: This information is specific to GSM networks, it is probably 90% valid for CDMA networks, but not WiFi.)

The short story is you cannot stop cell phone tracking.

Cellular mobile phone networks require location and identity information of device to operate. This location data is not derived from GPS data, it is intrinsic to cellular phone technologies.

I have seen stories of people removing device location information from the networks and maintaining connectivity, but I have yet to see actual proof. It is probably possible, but my opinion would be it would require co-operation from mobile networks to modify home location register records (The HLR is database which tracks device and user identity and location)

Without location data the cellular device will not interact with the network correctly and as a result phone calls and IP traffic (web, e-mail, Angry Birds, Facebook) will not function correctly. Period.
 
Since you've mentioned companies and governments I'll answer both briefly:

Companies -
- - To stop 99% of companies from tracking your location, do not use IP network services. 
- - The 1% who will be able to track you is the network carrier and what ever companies they share your location data with.

- - If you must use IP services (web, mail) use Orweb or Firefox browser with privacy plugins (I'd like to hear other opinions), TextSecure for SMS, RedPhone for voicecalls.

Governments:
- - Do not use a mobile cellular phone.

Notice above I mentioned location and identity information of the device. 

The network does not need to know the user - so a better approach is to use prepaid SIM cards and use Tor / Orbot/Orweb (for Web) and end-to-end encryption services like TextSecure (SMS), RedPhone (voice calls), PGP encrypted e-mail.

Regarding the location information, you might be interested in a short presentation I gave on the subject of location and identity. [1] I'd be interested in feedback.

regards,
Bernard

[1] http://www.ei8fdb.org/doku.php?id=mobseccij


On 24 May 2013, at 20:56, Yosem Companys wrote:

> From: Dan Gillmor <dan at gillmor.com>
> 
> Given the vanishingly small likelihood that companies or governments
> will do anything about cell phone tracking, I'm interested in what
> countermeasures we can take individually. The obvious one is to turn
> off GPS except on rare occasions.
> 
> I'll be discussing all this in an upcoming book, and in my Guardian
> column soon. So I'd welcome ideas.
> 
> Dan
> --
> Too many emails? Unsubscribe, change to digest, or change password by emailing moderator at companys at stanford.edu or changing your settings at https://mailman.stanford.edu/mailman/listinfo/liberationtech

- --------------------------------------
Bernard / bluboxthief / ei8fdb

IO91XM / www.ei8fdb.org

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