Visit ArabTopics.com

IMSI Catching: Phone surveillance measures and countermeasures go mainstream

phone-and-simcard-1280x720-istockphoto

Activism: The German newspaper Die Zeit has a long feature this week about IMSI catchers and their countermeasures, words that were long heard only in countersurveillance cultures at Black Hat and Defcon. Observing this phenomenon make the jump from the obscure to the mainstream tells us a lot about the years to come: surveillance and countersurveillance will be a cat-and-mouse game for quite some time.

Most people have heard of their IMEI, their phone’s unique identifier. It’s short for International Mobile Equipment Identity, and a lot of people learn how to read this number. Originally, it was produced by typing ×#06# on your phone, a sequence that amazingly still works, but it’s also on the phone receipt, in the menus, and in a number of friendlier places. This is the number you can insure, and this is the number you can report stolen to brick the phone.

A more secretive number is the IMSI, the Subscriber Identity, which identifies not the phone but the SIM card inside the phone. In most parts of the world, you’re expected to buy these separately from the phone, and you can replace the SIM card to change carriers but keep the same phone. In some other parts of the world, where telco carries have exercised regulatory capture and have a dysfunctional market, the SIM is typically card prebaked into the phone, and in these countries, you might never have seen it – but it’s still there, identified by the IMSI.

There are many good technical reasons to keep this number a secret. For example, any reconfiguration instructions sent to the phone from the carrier – so-called Over-the-Air provisioning — must be signed cryptographically with the IMSI of the current SIM card, in order to prevent fraudulent configuration. It’s also the number used when the phone contacts the carrier network, and therefore, anybody intercepting that handshake will see the IMSI.

This is the technology used in so-called IMSI catchers. When there is a large number of people in an area that the regime — police or other forces — want to keep tabs on, they deploy high-powered fake celltowers that the phones connect to, believing that these fake celltowers are their carrier’s. The fake towers then contact the real ones in turn, performing what we call a man-in-the-middle attack, which is just what it sounds like, sitting between the phones and the real cellphone towers.

This is a fairly sophisticated attack, one made by law enforcement in a highly dubious legal area. That’s why it’s really interesting to see mainstream media cover the topic now.

It’s particularly interesting as law enforcement won’t immediately get identities out of this attack — it will merely read which IMSI numbers were in the area at the time of the man-in-the-middle attack. Some of the time, this could conceivably be translated into people’s actual names, by means of subpoenas or similar to the carriers. A lot of the time, it won’t (think anonymous prepaid SIM cards).

While this attack can be used to track an individual’s movements once you have their IMSI — and has been used for this, notably with the American-made Stingray devices — it’s more alarming that law enforcement is increasingly using the attack to keep a catalog over which people, or at least their phones, are present at a certain type of protest.

Die Zeit’s article also covers countermeasures to the IMSI catcher attack, and mentions that while there are numerous apps that detect IMSI catchers, the better ones can only detect about 90% of those attacks.

We can expect this to escalate in the coming years.

Syndicated Article
This article was previously published at Private Internet Access.

(This is a post from Falkvinge on Liberty, obtained via RSS at this feed.)

Source: 
Rick Falkvinge

Dear friends of this aggregator

  • Yes, I intentionally removed Newsbud from the aggregator on Mar 22.
  • Newsbud did not block the aggregator, although their editor blocked me on twitter after a comment I made to her
  • As far as I know, the only site that blocks this aggregator is Global Research. I have no idea why!!
  • Please stop recommending Newsbud and Global Research to be added to the aggregator.

Support this site

News Sources

Source Items
Grayzone Project 13
Pass Blue 57
Dilyana Gaytandzhieva 14
John Pilger 410
The Real News 367
Scrutinised Minds 27
Need To Know News 1692
FEE 3256
Marine Le Pen 231
Francois Asselineau 25
Opassande 53
HAX on 5July 220
Henrik Alexandersson 547
Mohamed Omar 242
Professors Blog 10
Arg Blatte Talar 37
Angry Foreigner 17
Fritte Fritzson 11
Teologiska rummet 32
Filosofiska rummet 71
Vetenskapsradion Historia 117
Snedtänkt (Kalle Lind) 177
Les Crises 1887
Richard Falk 116
Ian Sinclair 80
SpinWatch 50
Counter Currents 6343
Kafila 360
Gail Malone 33
Transnational Foundation 221
Rick Falkvinge 93
The Duran 6564
Vanessa Beeley 93
Nina Kouprianova 9
MintPress 4817
Paul Craig Roberts 1157
News Junkie Post 45
Nomi Prins 24
Kurt Nimmo 191
Strategic Culture 3484
Sir Ken Robinson 16
Stephan Kinsella 66
Liberty Blitzkrieg 796
Sami Bedouin 61
Consortium News 2154
21 Century Wire 2917
Burning Blogger 281
Stephen Gowans 67
David D. Friedman 128
Anarchist Standard 16
The BRICS Post 1465
Tom Dispatch 411
Levant Report 17
The Saker 3442
The Barnes Review 472
John Friend 366
Psyche Truth 146
Jonathan Cook 135
New Eastern Outlook 3117
School Sucks Project 1736
Giza Death Star 1566
Andrew Gavin Marshall 15
Red Ice Radio 567
GMWatch 1809
Robert Faurisson 148
Espionage History Archive 34
Jay's Analysis 744
Le 4ème singe 87
Jacob Cohen 197
Agora Vox 10816
Cercle Des Volontaires 417
Panamza 1648
Fairewinds 103
Project Censored 721
Spy Culture 370
Conspiracy Archive 66
Crystal Clark 11
Timothy Kelly 490
PINAC 1482
The Conscious Resistance 547
Independent Science News 66
The Anti Media 5581
Positive News 820
Brandon Martinez 30
Steven Chovanec 61
Lionel 259
The Mind renewed 211
Natural Society 2467
Yanis Varoufakis 814
Tragedy & Hope 122
Dr. Tim Ball 65
Web of Debt 125
Porkins Policy Review 347
Conspiracy Watch 174
Eva Bartlett 563
Libyan War Truth 280
DeadLine Live 1905
Kevin Ryan 61
BSNEWS 1966
Aaron Franz 187
Traces of Reality 166
Revelations Radio News 121
Dr. Bruce Levine 111
Peter B Collins 1339
Faux Capitalism 205
Dissident Voice 9550
Climate Audit 220
Donna Laframboise 356
Judith Curry 1052
Geneva Business Insider 40
Media Monarchy 1991
Syria Report 70
Human Rights Investigation 90
Intifada (Voice of Palestine) 1685
Down With Tyranny 10133
Laura Wells Solutions 27
Video Rebel's Blog 411
Revisionist Review 485
Aletho News 17865
ضد العولمة 27
Penny for your thoughts 2660
Northerntruthseeker 2046
كساريات 37
Color Revolutions and Geopolitics 27
Stop Nato 4617
AntiWar.com Blog 2692
AntiWar.com Original Content 6120
Corbett Report 2088
Stop Imperialism 491
Land Destroyer 1107
Webster Tarpley Website 941

Compiled Feeds

Public Lists

Title Visibility
Funny Public