Wireless wises up

Hogs and hackers

Replacing hardware with software in a radio frequency device makes it much more flexible. Unfortunately, it also makes it more vulnerable to abuse, according to Jung-Min Park, a professor at Virginia Polytechnic Institute in Blacksburg.

A target application of cognitive radio is to let unlicensed users legally use portions of the radio spectrum that are officially reserved for licensed users -- as long as they can do so without interfering. A way to implement that is to have radios share information about which spectrum bands are in use and which are idle. Park says the danger comes from a phenomenon called spectrum hogging, in which an adversary radio sends false data in order to commandeer slices of spectrum for its own use.

Another danger: Since software- defined radios can be modified from afar, hackers could download malicious software to them. Park says he's looking for algorithms that might detect such attempts. "These are security issues that can't be solved by traditional countermeasures such as cryptography," he says.