Transcript Wireless Security

AJ Mancini IV
Paul Schiffgens
Jack O’Hara
WIRELESS SECURITY
WIRELESS SECURITY
 Brief history of Wi-Fi
 Wireless encryption standards
 WEP/WPA
 The problem with WEP
 WPA/WPA2
 Recommend use of WPA on home networks
WIRELESS SECURITY
 First wireless local area network (WLAN)
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ALOHAnet
University of Hawaii – 1970
Norman Abramson
Seven Computers, Four Islands
 More publications to IEEE
 ~ 1980
 Including infrared and CDMA
WIRELESS SECURITY
 802.11 Committee
 Institute of Electrical and Electronic Engineers
(IEEE)
 IEEE 802.11-1997 – First Industry Standard
 Followed by 802.11a/b/g
WIRELESS SECURITY
 WEP
 Wired Equivalent Privacy
 Part of original 802.11 standard
 Deprecated in 2004
 Still included in standard
WIRELESS SECURITY
 Problems with WEP
 40-bit or 104-bit key with 24-bit Initialization
Vector (IV)
 Government restriction on cryptography
 WEP uses an RC4 stream cipher
 Paramount that the same IV never be used twice
 Problem: 50% chance that an IV will repeat after
5000 packets
WIRELESS SECURITY
 Published attacks on WEP encryption
 Scott Fluhrer, Itsik Mantin, Adi Shamir published
crpytanalysis of RC4
 aircrack-ng – crack any WEP key in minutes,
regardless of size or complexity
WIRELESS SECURITY
 Published attacks on WEP encryption
 2005 – FBI demonstration
 Andreas Klein expands on previous work,
exposing more weaknesses in the RC4 cipher.
WIRELESS SECURITY
 Published attacks on WEP encryption
 Erik Tews, Andrei Pychkine, Ralf-Philipp
Weinmann extend Klein’s work and apply RC4
weaknesses to WEP key recovery , develop new
attack
 104-bit key
 40,000 packets – 50% recovery
 60,000 packets – 80% recovery
 85,000 packets – 95% recovery
 Using packet injection, 40k packets can be
generated in under 1 minute
WIRELESS SECURITY
 Problems with WEP identified
 WEP deprecated in 2004
 802.11i – Standard introduced Wi-Fi Protected
Access (WPA)
 Problem:
 WEP is still included for compatibility with older
equipment, is often the default form of security on
consumer-level wireless equipment
 Further problem: most equipment comes without
any form of security enabled by default
WIRELESS SECURITY
 WPA2
 Can utilize Advanced Encryption Standard (AES)
encryption
 Government-qualified for Top Secret
 Cipher has no known vulnerabilities
 Only successful exploits are cross-channel attacks
 Attacks made against implementation, not cipher
 Disadvantage – requires hardware support
WIRELESS SECURITY
 Recap
 WEP 64/128 – 24 bit IV + 40/104 bit key
 IVs must be unique – vulnerability
 5000 IVs before repeat
 WPA2 w/ AES
 Top Secret-grade encryption
 No vulnerabilities in the cipher
 Authenticated and Encrypted
WIRELESS SECURITY
 Recommend immediate adoption of WPA2
over WEP, unsecured networks