Ben Burgess General Exam Presentation - Friday May 18, 2018 at 10:00 am - CS302 Title: "Security Evaluation of Trunking Abstract; Trunking radio is used as the primary communication system for almost all large commercial and government agencies. These radio system provide more convenience than most cellular phones or conventional two way radios can provide while also in most cases promising the ability to provide completely secure communications. On top of providing the ability to use secure voice, trunking radio vendors offer solutions to rekey the radios over the air in the case that a radio is lost or stolen. In this paper, we select trunking radio solutions from the two dominant vendors in the market, Motorola and Harris. We implement a proof of concept attack that had been previously theorized [Glass 2011] against a real world deployment of the Motorola trunking radio solution. We then extend this attack to compromise the security guarantees the over the air rekey system was thought to provide. We continue on to reverse engineer the protocol specification of the Harris solution which was previously tightly controlled and unavailable for public inspection. We then design an attack against this system which allows for an adversary to both intercept and forge traffic between the subscriber unit and base station. Barbara A. Mooring Interim Graduate Coordinator Computer Science Department Princeton University