Hacking_and_Penetration_Testing_with_Low_Power_Devices

Adding security
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a different channel and PAN ID has little chance of being noticed. This is a form of
security through obscurity that is not really security at all.
You may be tempted to just automatically start encrypting all your traffic. Before
you do so, realize that there are certain drawbacks to adding encryption. First,
encryption adds computational overhead. Second, encryption increases latency
thanks to the time it takes to encrypt and decrypt each packet. Third, the maximum
packet size is reduced when encryption is enabled. This means that more packets will
be required and that some of the scripts provided in this chapter must be updated
when encryption is used. Finally, encryption adds complexity. If all modems aren’t
using the same encryption key, things will not work properly. These types of problems
tend to be hard to diagnose.
Should you decide to encrypt an XBee network, the process is straightforward.
For Series 1 modems, enable encryption by setting the EE (encryption enable)
parameter to 1 and then store your chosen AES encryption key (of at most 32 characters)
in the KY variable on each modem in the network. Don’t forget to save your
changes to the modem. Note that the KY value cannot be read, only set. Figure 7.11
shows how these values can be set in the X-CTU software.
Enabling encryption on Series 2 routers and end devices is very similar to the
Series 1 case. The EE value is set to 1 and the KY value to the chosen key. Setup
of a router is shown in Figure 7.12. The coordinator in a ZigBee network has an
FIGURE 7.11
Enabling encryption with Series 1 XBee modems.