With more organizations using mobile broadband networks, IT managers should be very concerned about security. Safeguarding data as it travels the airwaves may be only part of a mobile security policy -- enterprises must secure their devices and the data they store -- but the airwaves are a good place to start.

The good news about wireless security is that today's mobile broadband networks have some enhanced security functions built in. The latest 3G technologies, including WiMax, have robust encryption options. AT&T and T-Mobile provide High Speed Packet Access with a 128-bit Kasumi encryption algorithm. CDMA2000, offered by Sprint and Verizon, sports 128-bit Advanced Encryption Standard encryption. WiMax also uses AES.

Encryption Not Guaranteed
The bad news is that there are major shortfalls with AES. One is that AES activation is largely optional on the part of operators. AT&T says its Kasumi encryption is always on, but Verizon wouldn't say whether that's the case for its encryption option. Moreover, even if your operator uses encryption, your users may roam onto a network that doesn't. And a 2G connection has much less robust encryption mechanisms than 3G, which are considered easy to defeat.

Finally, channel encryption only extends to an intermediate point within the cellular network. After that, data travels unencrypted until it reaches the far end of a connection, where most communication is again locked down.

Some operators offer network VPNs or private circuits, e.g., frame relay, for the unencrypted portion of your data's journey, so there are some options on the back end if you have a lot of data business with an operator. But these options can be complicated. Even if your radio link is reasonably secure, there's the problem of users connecting via other access networks, such as unprotected Wi-Fi hotspots. Wi-Fi capability is the norm for laptops and increasingly is available on smartphones.