Security researchers Jos Wetzels, Carlo Meijer, and Wouter Bokslag shared their research on TETRA technology by reverse engineering Motorola MBTS and MTM5400 radios and extracting the secrets from them.

TETRA is a radio technology patented in 1995 and based on proprietary cryptography. Equipment using this protocol was developed for law enforcement and military clients, as well as for 0T and SCADA systems used in machine-to-machine communication. So, the impact is huge.

The authors also identified traces of the first attacks on TETRA dating back to 2009. It looks like an NDA is not enough to protect against hackers.