On Mar 19, 2004, at 6:35 PM, Russ Button wrote:
If a wireless network is properly configured with other than a default SSID and with WEP encryption, how difficult is it to crack? I'd assume that the WEP encryption gets harder to crack the more bits it has.
Not by much though. The Fluhrer attack is linear with respect to the key size, i.e. 256 bits is not much different from 64 bits.
How long does it take someone with a good laptop to crack WEP encryption at:
64 bit 128 bit 256 bit
If you have current firmware, you're vendor is probably using weak IV filtering. This prevents the Fluhrer et. al. attack (airsnort, bsdairtools), but reduces the IV space such that building a dictionary of <IV,cipher> is easy to do (inductive attack). The time it takes to build the dictionary depends on the aggressiveness of the filtering. But, you have a few hours of security regardless of the key size as the inductive attack depends on the size of the IV space not the size of the key.
The long and short of it is don't use WEP if you care about security. Most vendors have TKIP available now, and that's what you should use until your vendor supports AES-CCM.
Bill
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