Chapter 13Approaches to Security
In Chap. 12 we discussed some of the problems associated with providing security to mobile computing. This chapter presents, at a high level, several approaches taken to protecting data. We will see these methods employed in subsequent chapters.
13.1 Limit the Signal
The first way to protect data is to limit the accessibility of the signal. At the lowest levels, this means restricting who can see the signal on the wire.
13.1.1 Wire integrity and tapping
In a traditional Ethernet, signals do not radiate far beyond the wire, so eavesdropping requires physical proximity to the network cable and physically tapping the line. This is done by splicing into the line (old “thick-net” Ethernet used “vampire” taps to add ...