The device can be viewed as simply a modified cell tower with a malicious operator, and on 4 January 2012, the Court of Appeal of England and Wales held that the patent is invalid for obviousness.
[8] Police departments have been reluctant to reveal use of these programs and contracts with vendors such as Harris Corporation, the maker of Stingray and Kingfish phone tracker devices.
The 3G wireless standard mitigates risk and enhanced security of the protocol due to mutual authentication required from both the handset and the network and removes the false base station attack in GSM.
An IMSI-catcher masquerades as a base station and causes every mobile phone of the simulated network operator within a defined radius to log in.
[15] The IMSI-catcher subjects the phones in its vicinity to a man-in-the-middle attack, appearing to them as a preferred base station in terms of signal strength.
[16] This means that the device will be able to retrieve data that a normal cell tower receives from mobile phones if registered.
Active IMSI-catchers generally also intercept all conversations and data traffic within a large range and are therefore also called rogue cell towers.
False base station attacks are prevented by a combination of key freshness and integrity protection of signaling data, not by authenticating the serving network.
This is a special type of mobile phone firmware that can be used to detect and fingerprint certain network characteristics of IMSI-catchers, and warn the user that there is such a device operating in their area.
But this firmware/software-based detection is strongly limited to a select few, outdated GSM mobile phones (i.e. Motorola) that are no longer available on the open market.