Is Your Cell Phone Talking to Your Carrier, or Behind Your Back to a Rogue?

It's not easy to tell, but very important if you want to have a confidential conversation.

What is a rogue or IMSI catcher?
"An IMSI catcher is essentially a false mobile tower acting between the target mobile phone(s) and the service providers real towers. As such it is considered a Man In the Middle (MITM) attack. It is used as an eavesdropping device used for interception and tracking of cellular phones and usually is undetectable for the users of mobile phones. Such a virtual base transceiver station (VBTS) is a device for identifying the International Mobile Subscriber Identity (IMSI) of a nearby GSM mobile phone and intercepting its calls." (more)

Folks with a Cryptophone know...

"Each week an increasing number of Cryptophone customers are becoming aware of disturbing, yet unfortunately not surprising changes to the cellular network in their area.

This screenshot sent in by a customer shows the Cryptophone 500 alerting them to changes in the mobile network. In this case standard network encryption has been turned off. This is often an indication that a rogue base station or “IMSI Catcher” is active in the area.

While this knowledge would be of great to concern to most people, Cryptophone users can rest easy knowing that even in the presence of an ‘active’ attack’s like this, their communications are still completely secure." (more) (more)

Think the problem is theoretical? 

"Recently leaked brochures advertising next generation spy devices give outsiders a glimpse into the high-tech world of government surveillance. And one of the most tantalizing of the must-have gizmos available from a company called GammaGroup is a body-worn device that surreptitiously captures the unique identifier used by cell phones." (more)

"Hacker intercepts phone calls with homebuilt $1,500 IMSI catcher, claims GSM is beyond repair" (more) 

"Septier IMSI Catcher (SIC) has been designed as a tactical solution intended to extract GSM entities. Based on the Septier GUARDIAN infrastructure, Septier IMSI Catcher provides its users with the capability of extracting IMSI and IMEI of GSM Mobile Stations (MS) that are active in the system's effective range.

Septier IMSI Catcher is the perfect solution for both extracting identities from MS in its area of coverage (when these identities are previously unknown) and detecting the presence of known cell phones in the area, notifying the system user about those phones. Septier IMSI Catcher can be equipped with an add-on 3G module that allows identity extraction for 3G cell phones as well. It has several configurations that allow meeting the specific requirements of every operation and are suitable for various working conditions." (more)