In a security briefing at this week's Intel Developer Forum in San Jose, Jesse Walker of Intel and Warren Barkley of Microsoft presented the current developments in 802.11 TGi -- an initiative designed to counteract the many security flaws in 802.11 wireless networking.
Walker was one of the first to uncover the problems in 802.11's Wire Equivalent Privacy (WEP) and thereby technical editor of the TGi working group. "Last year, we couldn't say that wireless networks could be made secure. Today, we can," he said.
He admitted that the solution was only suitable for professionally administered enterprise networks, and that consumers would remain unprotected until at least the end of 2003. "There aren't many of us working on this, and we have to get the groundwork done first. Absolutely it's a problem. People should be worried!" he told ZDNet UK.
The new system uses a combination of techniques, none particularly strong in a cryptographic sense but secure together. It doesn't require new hardware, as it is only a subset of the full 802.11 TGi system, which will need new hardware and is due to be approved next year.
This year's system, called SSN but due to be renamed, uses an authentication system called 802.1x that positively identifies the user and the access point to each other, and then provides keys for TKIP, a WEP replacement. TKIP is "data confidentiality that works," said Walker. It encrypts the network information through a combination of medium-strength cryptography and reissuing keys.
802.1x requires an access server running a user authentication protocol such as RADIUS, which makes it unsuitable for consumer use on a home network, but does integrate well with existing enterprise security systems.
Some of the limitations of SSN are due to the requirement of making it work on existing hardware; this has limited processing power, which is nearly fully occupied in managing ordinary network traffic. The result: there is little overhead in access points for adding the system software necessary to make systems secure until TGi is approved and available. Administrators should contact their vendors for software patches to add SSN.
Adding SSN to an existing network is not complex: Microsoft upgraded its own worldwide 32,000-node 802.11b wireless network to the new system in two weeks.
Barkley identified 802.11's ease of use as one of the security issues, pointing out that the Microsoft wireless LAN started as a trial system that was wildly popular and grew out of control.
"You can't stop wireless networking," he said. "It's a drug, once you've tried it you don't want to stop. If a company won't roll out 802.11, then users buy access points and plug them in -- they don't even enable WEP." He identified the rogue access point as one of the five major areas where more work was needed: the others were ease of use, managing users, securing ad-hoc networks where no access point was present, and coping with denial of service attacks.
"Although everyone worries about privacy and data security," said Walker, "the bigger threat is preventing the bad guy from accessing your network to do bad things."