So if you transmit data through the air, such that anyone can read it without any physical security, it’s not a question of if the encryption used it broken, but when.

From ITWorld,

Security researchers say they’ve developed a way to partially crack the Wi-Fi Protected Access (WPA) encryption standard used to protect data on many wireless networks.

The attack, described as the first practical attack on WPA, will be discussed at the PacSec conference in Tokyo next week. There, researcher Erik Tews will show how he was able to crack WPA encryption, in order to read data being sent from a router to a laptop computer. The attack could also be used to send bogus information to a client connected to the router.

Clearly you have to assess what you use your wireless for and how likely it is for someone to be listening in, but it’s growing more and more clear that any broadcast technology is going to be broken eventually.

Update 7th November 2008.

It’s not as bad as it first sounded, but it’s still an issue.  Read more here.