Public Sector Case StudyThe U.S. military needed a way to communicate information quickly and securely in the rapidly changingenvironment of a battlefield. Wired communications, while secure and robust, had significant drawbacks.Communications lines could easily be severed and military personnel were limited to only communicating with fixedlocations. Radio and wireless communications removed the threat of cut lines, and extended the range ofcommunications, allowing military personnel to communicate with mobile units, but only to a fixed range. Stationaryinstallations were still needed as base stations, and throughput degrades the further units were from the base station.That led the military to turn to a new type of wireless networking called wireless mesh networking.Wireless mesh networks are based on a distributed network mesh topology. Each node in the network connects tomultiple nodes; each node also acts as a router for the nodes it connects to allowing traffic to hop along multiple pathsto a destination. This allows for a very robust and flexible network. The loss of one node will not hurt the network, andnodes can be added at will. Range of the total network is also massive because nodes don’t need to be close to a centralpoint. They just need one other node to function. An example of a mesh network can be seen in Figure 6-2.While a wireless mesh network solved part of the military’s requirements, security remained a major concern. Tomake sure the communications were secure the military implemented both physical and logical access controls on thenetwork.For the physical security of the communications, the military uses frequency hopping on the radios connected to thenetwork. The radios are constantly changing frequencies. This allows them to avoid jamming and eavesdropping.For logical security the mesh network relies on MAC addressing to identify all of the devices in the network. A list ofall allowed Media Access Control (MAC) addresses is generated and each device knows whom it talks to. A MACaddress can be faked, so they also utilize a shared secret style encryption key to handle security. When devices in thenetwork first link together, they will authenticate each other utilizing public key infrastructure (PKI) then develop ashared key, which will get renewed periodically to handle encryption. Now any communications between nodes can bevalidated with that key. These two network access controls methods give the military the ability to secure theirwireless communications.submit a case study on Public sector.
