WEP is insecure

[Steve Kennedy]

Just FYI, from a work colleague.

A couple of weeks ago a theoretical paper was published that discussed a
weakness in RC4 key scheduling... and observed that the way in which WEP
(link layer encryption for 802.11 wireless networks) worked meant that
they should be considered insecure...

There is now a practical demonstration of this:

    http://www.cs.rice.edu/~astubble/wep/wep_attack.pdf

It took a summer intern about a week to mount the attack from start to
finish...  expect the script kiddies to be able to do it pretty much
instantly from now on :-(

The recommendations in the report are extremely relevant to anyone using
such a system at home or at work:

    Given this attack, we believe that 802.11 networks should be viewed
    as insecure. We recommend the following for people using such
    wireless networks.
        * Assume that the link layer offers no security.
        * Use higher-level security mechanisms such as IPsec and SSH for
          security, instead of relying on WEP.
        * Treat all systems that are connected via 802.11 as external.
          Place all access points outside the firewall.
        * Assume that anyone within physical range can communicate on
          the network as a valid user. Keep in mind that an adversary
          may utilize a sophisticated antenna with much longer range
          than found on a typical 802.11 PC card.


Steve

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