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A Daily Digest of IT Blogs from Richi Jennings

Wi-Fi encryption "cracked in 60 seconds"... time to panic?

It's reported that security researchers have broken WPA Wi-Fi encryption. Is that really true, or is it just the usual silly summer linkbait? In IT Blogwatch, bloggers unpick the breathless reporting and tell us what's really happening.

By Richi Jennings. August 28, 2009.

Your humble blogwatcher has selected these bloggy morsels for your enjoyment. Not to mention peripherals...

Nate Anderson dons his tinfoil hat:

Researchers have come a step closer to breaking open a common WiFi encryption scheme. An attacker can now read and falsify short packets in the common TKIP version of WiFi Protected Access (WPA) encryption in about one minute—a huge speed increase from the previously-required 12-15 minutes..
...
The current attack comes courtesy of Toshihiro Ohigashi (Hiroshima University) and Masakatu Morii (Kobe University), and it is outlined in a new paper (PDF) of theirs called "A Practical Message Falsification Attack on WPA." It builds on 2008 research from a pair of German students, research that also attacked WPA TKIP systems and could read individual packets, crafted new data for them, then recalculate a legitimate packet checksum.more


Nick Farrell offers this inoffensive, lepidopteroid racial stereotype:

Japanese boffins took time out from fighting giant moths to work out how to break the WPA encryption system used in wireless routers in just sixty seconds. ... It has been known that WPA could be broken for some months now, but these researchers have come up with a theoretical attack and made it practical.
...
Both attacks work on WPA systems that use the Temporal Key Integrity Protocol (TKIP) algorithm ... [which] is a bit long in the tooth. It was designed as an interim encryption method as WiFi security was developing. ... However there is still a fair bit of WPA with TKIP kit out there since 2006. Newer WPA2 devices that use the stronger Advanced Encryption Standard (AES) algorithm remain safe for now.more


Jose Vilches looks back:

The attack builds on the so-called "Becks-Tews method" unveiled last year by researchers Martin Beck and Erik Tews. However, that method worked on a smaller range of WPA devices and took between 12 and 15 minutes to carry out. Both attacks work on WPA systems that use the Temporal Key Integrity Protocol (TKIP) algorithm.
Ā 
They aren't key-recovery attacks -- but give hackers a way to read encrypted traffic sent between computers and certain types of routers that use the outdated encryption system.more


Glenn Fleishman gets technical:

Ohigahi and Morii use a physical man-in-the-middle (MitM) as part of their solution. ... A directional antenna that lets them intercept and reuse an ... initialization vector (IV) ... the station only receives the falsified packet, and thus doesn't receive an out-of-sequence number. This mostly likely requires a directional antenna which can overpower the broadcast of the access point for a given client; it might also work with a distant omnidirectional access point if the attacker had a more powerful omni.
...
The ... approach has other refinements, such as monitoring the network for periods of low usage and then switching from the pure repeater mode into a key recover mode in which the malicious party attempts to recover the encrypted checksum, blocking communication between the station and access point during this time. ... They reduce the time necessary for a crack by making additional assumptions about ARP packets that let them solve for the checksum about 37 percent of the time, and check whether they've recovered the key.more


But Scott Merrill couldn't care less:

Be like me, and forget trying to encrypt your transmission method, and rely instead on strong encryption at the protocol level. All of the wireless networks I’ve set up at home have been wide open. If you’re not using SSL or TLS for your traffic anyway, you’re doing something wrong. Besides, I hate having to key in security details when I visit friends’ ā€œprotectedā€ wireless networks.more


To sum up, William Garrison mans the harpoons:

TKIP was fundamentally broken, by design. ... It allowed router manufacturers to use something better than WEP without having to beef-up their hardware. It worked well, and bought several years before it was completely broken.
Ā 
Anyone who has a router using TKIP bought at a bad time, and is stuck with something that's only a little better than WEP.more


So what's your take?
Get involved: leave a comment.



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Richi Jennings is an independent analyst/consultant, specializing in blogging, email, and spam. A 24 year, cross-functional IT veteran, he is also an analyst at Ferris Research. You can follow him as @richi on Twitter or richij on FriendFeed, pretend to be Richi's friend on Facebook, or just use good old email: itblogwatch@richij.com.

What People Are Saying

I would assume (probably

I would assume (probably incorrectly) that all encryption should be breakable, at least by the manufacturer, or else it's impractical. Any developer of encryption software needs to be able to break their own encryption in order to have the decryption algorithms. Am I way off here?

comments

No, not a time to panic, as this is expected.
A wise man once said. "If a man encrypts it, then another man can decrepit it".
So what ever we do, someone will be able to hack it at some point.

Not hype, but not a crack

The hype came from pundits and reporters who didn't actually read the paper nor understand what it contained.

Thanks for the link to my technical rundown; some of the other folks you link to have the right idea. This isn't a key-recovery attack that threatens TKIP (not WPA; WPA is a certification rubric). It's a very narrow and interesting exploit that allows the recovery of per-packet key when you know nearly everything in the packet already.

But it's more sexy to say, gone in 60 seconds.

Oh, goody. Now I can count

Oh, goody. Now I can count on a new pile of obsolete wireless devices. WPA2(AES), here I come!