Law enforcement agencies thrive on information. In previous eras, it was sufficient to receive information through the police dispatch radio. Today, much more than voice based information is required. Officers often need to check vehicle registrations, personal identities, outstanding warrants, mug shots, maps, and the locations of other officers. 

One major difficulty with meeting this need for more information is figuring out how to transmit the data to remote and mobile locations. Local police agencies are sometimes able to restrict their transmission needs to within the city limits. However, county sheriffs and state troopers often have to travel to remote locations that aren’t within a metropolitan area’s boundaries.

Suppose a rural county sheriff’s department has received a grant to upgrade its existing voice-only communication system. Among other requirements, the grant specifies that all communications must be protected against eavesdropping and unintended information disclosure. 

Your assignment: Recommend specific controls to be applied to radio, cellular, and satellite transmissions. How will you ensure that only sheriffs and other authorized users can use the system?