  IMSI Catchers are tracking devices that break the privacy of the subscribers
of mobile access networks, with disruptive effects to both the communication
services and the trust and credibility of mobile network operators. Recently,
we verified that IMSI Catcher attacks are really practical for the
state-of-the-art 4G/LTE mobile systems too. Our IMSI Catcher device acquires
subscription identities (IMSIs) within an area or location within a few seconds
of operation and then denies access of subscribers to the commercial network.
Moreover, we demonstrate that these attack devices can be easily built and
operated using readily available tools and equipment, and without any
programming. We describe our experiments and procedures that are based on
commercially available hardware and unmodified open source software.
