Can my cell phone be tapped? 

Risks associated with the use of GSM cell phones

In our modern business world it is unimaginable to do without mobile communication. The cell phone has become an integral part of today's life.

While more and more often even sensitive or critical communication is held over the mobile network, the criminal interest in GSM transmissions has been increasing in equal measure: Mobile phones are, in surveillance terms, a major liability.

There are two different major risks associated with the use of cell phones:

Technical tapping of the mobile calls

Next to physical manipulation of a device, there exist today several methods, which allow the remote tapping of a cell phone and do not require direct access.

It is true that the communication signals are encrypted between the mobile phone and the GSM base station antenna mast, but this data stream nowadays can be decrypted with a common Personal Computer. Furthermore, the transmission between the sending antenna mast and the receiving antenna mast contains no encryption at all.

The standard GSM encryption algorithm is deemed to be unsecure ever since the nineties, since then the decryption methods have advanced continuously.

Remotely activated mobile phone microphones

Another threat is posed by the possibility to use a cell phone to listen in on conversations in the surroundings of the device. For that purpose the microphone of the corrupted device is activated remotely by an incoming call, without any noticeable sign or ring tone. Even an apparently switched off device could be misused that way.

There exist a variety of different methods to gain access to a third party mobile phone. Here you can find a short description of the most common tapping scenarios:

• IMSI-Catcher

• Cell Phone Spyware

• Man-in-the-middle-attack