Saturday, June 19, 2010

WEP, TKIP Declared Out…

If the fast spreading news on the Internet is to be believed, Wi-Fi alliance has decided to drop off WEP and TKIP encryption techniques from its certification criteria.

WEP was the only encryption techniques mentioned in the original IEEE 802.11 standard. Some flaws in the WEP encryption algorithm were discovered just after two years of release of WiFi standard and it was cracked in 2001. Since then several attacks on WEP have been published e.g. FMS attack, Korek attack, chop-chop attack, fragmentation attack, Aircrack-PTW attack, Caffe Latte attack etc.

TKIP was an enhancement over WEP. It was an attempt to provide better security to legacy WEP encryption capable devices and hence same RC4 technique with some modification was used in TKIP. The first and only attack on TKIP was published by Martin Beck and Erik Tews in 2008, five years after the release of TKIP specification for WiFi encryption. The attack was about injection of few small sized frames in the client to cause some disruption. It was not a key retrieving attack and unlike WEP, data privacy was guaranteed in TKIP.

The migration towards only-AES encryption mode will be done in stages over three years starting from 2011. From 2011, WiFi alliance will stop certifying APs with WEP or TKIP configuration. In 2012, wireless client devices will be axed for their support for WEP or TKIP. Starting from 2014, new WiFi devices which support only AES encryption will be certified. These requirements must be easily satisfied by device vendors by masking the disallowed encryption techniques just by applying software patch on the newly manufactured devices and if it happens, this will be a great move towards much needed secured wireless world.

A very interesting observation to note here is that the default configuration of most out of the box access points is “Open” which is a much bigger evil than WEP or TKIP. If a wireless LAN is operating in open mode all types of wireless attacks are possible e.g. data snooping, impersonation, unauthorized access to the network etc. The ideal move would be to support only one configuration in the Access Point and Client with the AES encryption as per the IEEE 802.11i and the IEEE 802.11w standard.

In short, the good (TKIP) and the bad (WEP) has been declared out but the ugly (Open configuration) will be continued to play!

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