The Final ‘Final’ Nail in WEP’s Coffin?

Researchers have discovered a new way of attacking Wired Equivalent Privacy that requires an amount of data “more than an order of magnitude” less than the best known key-recovery attacks. In effect, the cracking can be done within a minute, as the title of the paper suggests: Breaking 104 bit WEP in less than 60 seconds.

Specifically, only 40,000 data packets are needed for a 50 percent chance of success, while 85,000 packets give a 95 percent chance of success, according to the paper’s authors: Erik Tews, Ralf-Philipp Weinmann and Andrei Pyshkin, all researchers in the computer science department at Darmstadt University of Technology in Darmstadt, Germany.

The ease of cracking WEP is nothing new; cryptanalysts showed six years ago that any WEP key can be cracked with readily available software in one minute or less. The protocol, which is part of the IEEE 802.11 wireless networking standard, was superseded by WPA (Wi-Fi Protected Access) in 2003, then by WPA2, another name for the full IEEE 802.11i standard.

What’s new that has been missing from WEP cracking until now is that a Wi-Fi attacker no longer needs long periods of time nor much smarts, according to Wi-Fi security experts.

“…To crack WEP [up until now] it 1) required a knowledgeable attacker [and] 2) took a long time,” said Andrea Bittau, in an e-mail exchange. Bittau is a research fellow at the University College London and a co-author of a paper describing what had been the most effective WEP cracking technique prior to the Germans’ research.

“In the past, the wait time could have been hours, whereas now, it seems to be only a few minutes,” Battau said. “Thus, WEP cracking has finally made it into the ‘general public’ at a reasonable cost [only a few minutes].”

Thanks to this new discovery, we can expect the arrival of tools that can break WEP in 10 minutes or less by pressing a single button, Battau said. In other words, tools that can allow for walk-through hackings, whether in Wi-Fi-networked conference rooms or in the local coffee shop.

Analysts speak out on wireless security hype. Click here to read more.

Battau’s Web cracking paper, published with Mark Handley of University College London and Netgear’s Joshua Lackey, was titled “The Final Nail in WEP’s Coffin.”

When published in May 2005, the paper presented a breakthrough in WEP cracking: a novel vulnerability that allows an attacker to send arbitrary data on a WEP network after having eavesdropped only a single data packet, along with techniques for real-time decryption of data packets that can be used under common circumstances.

If that “final nail” wasn’t the final nail, will this new research be the one that really puts WEP into its grave?

David Wagner, co-author of a paper on the insecurity of 802.11, said he’d like to think it’s the last nail for WEP, but we’re probably not going to see the end of it soon.

Next Page: WEP is everywhere despite warnings.