1. Wireless Ethernet
802.11 Presentation 3
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2. How do we make a buck with
802.11
 Setup secured hot spots for client access.
Sales force that is constantly mobile.
Wireless internet service Provider.
 Working with communities to offer free
WiFi.
 Combining Office networks to share one
connection.
 Implementation of sound security for
users. Consult and configure network
security.
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3. 802.11 Offers
 Roaming freedom
◦ No longer constrained to the office
◦ Smaller devices now have same function as
laptops and tablets
◦ Never have to worry about access to external
and internal network resources.
◦ Real Time Data Updates – Workers in the field
can receive information in real-time.
◦ High Speed Data Transmission – Very close to
LAN speeds and faster then Dial up.
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4. 802.11 Security and Privacy
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5. Authentication and privacy
 Goal: to prevent unauthorized access & eavesdropping
 Realized by authentication service prior access
 Open system authentication
◦ station wanting to authenticate sends authentication
management frame - receiving station sends back frame
for successful authentication
 Shared key authentication (included in WEP*)
◦ Secret, shared key received by all stations by a separate,
802.11 independent channel
◦ Stations authenticate by a shared knowledge of the key
properties
 WEP’s privacy (blocking out eavesdropping) is based on
ciphering:
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*WEP: Wired Equivalent Privacy

6. 802.11 Wired Encryption Protocol
 Part of 802.11 specification
 Shared key – 40/104 bits
 Initialization vector (IV) = 24 bits
 Uses RC4 for encryption
 WEP2 added, increases key length to 128 bits
http://i.msdn.microsoft.com/Aa503279.Native_802_11_wep(en-us,MSDN.10).gif
http://www.cs.wustl.edu/~jain/cse574-06/ftp/wireless_security/fig14.gif
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7. 802.1x Access Control
• Designed as a general purpose network access control
mechanism
• Not Wi-Fi specific
• Authenticate each client connected to AP (for WLAN) or switch
port (for Ethernet)
• Authentication is done with the RADIUS server, which ”tells”
the access point whether access to controlled ports should be
allowed or not
• AP forces the user into an unauthorized state
• user send an EAP start message
• AP return an EAP message requesting the user’s identity
• Identity send by user is then forwared to the authentication server
by AP
• Authentication server authenticate user and return an accept or
reject message back to the AP
• If accept message is return, the AP changes the client’s state to
authorized and normal traffic flows
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8. 802.1x Access Control
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9. Wireless Protected Access
(WPA)
• WPA is a specification of standard based, interoperable
security enhancements that strongly increase the level of data
protection and access control for existing and future wireless
LAN system.
• User Authentication
• 802.1x
• EAP
• TKIP (Temporal Key Integrity Protocol) encryption
• RC4, dynamic encryption keys (session based)
• 48 bit IV
• per packet key mixing function
• Fixes all issues found from WEP
• Uses Message Integrity Code (MIC) Michael
• Ensures data integrity
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