Unauthorized access could manifest itself as MAC address
spoofing, as a man-in-the-middle attack, as a session-hijack or as message
contamination.
1.2 802.11i in Sensor Networks
Reacting to the security weakness in 802.11, the IEEE 802.11 standards committee
sought to provide additional security features with the 802.11i specifi-
423
School of Electrical and Computer Engineering Atlanta, GA 30332
Georgia State University Atlanta, GA 30303
,
,
Cherita Corbett, John Copeland, and Raheem Beyah
cation [2]. 802.11i primarily improves encryption via the Advanced Encryption
Standard (AES), which requires significantly more computing power than the
original standard. To be e?®ective, 802.11i requires new hardware and must
be commonly applied to all systems on the wireless network. An implementation
of 802.11i in sensor networks would require each sensor to take the
Supplicant, Authenticator, and Authentication Server roles to enforce its own
security policy. Each sensor must authenticate each peer (even sensors that are
functioning as relay nodes) and maintain a set of keys for each peer relationship.
The required computing power coupled with the density and dynamically
changing topology of sensor networks renders 802.11i an impractical solution.
The 802.11i standard is better suited for non-transient, centralized networks
with fixed infrastructure. Further, the 802.11i protocol works well against defending
the nodes within the network from an outsider threat, but does little
to protect authorized nodes from other authorized nodes.
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