This document discusses wireless security using WPA2. It begins by describing the types of wireless security including open networks, WEP, WPA, and WPA2. It then provides an overview of WPA2, including how it uses AES for encryption and integrity checking. The document compares WEP, WPA, and WPA2 and describes WPA2 authentication in personal and enterprise modes. It details how WPA2 generates keys through a 4-way handshake and uses AES in counter mode for encryption and CBC-MAC for integrity. The document concludes by discussing benefits and vulnerabilities of WPA2 as well as procedures to improve wireless security.

1. WIRELESS SECURITY USING
WPA2
BY :
TUSHAR ANAND KUMAR
ECE-”D”, REGD. NO.:
1151016015

2. CONTENTS
• Types of security in WLAN
• Comparison of WEP,WPA,WPA2
• Evolution of wireless security standards
• WPA 2 authentication ,encryption & decryption
• Benefits & vulnerabilities
• Solutions & conclusion

3. TYPES OF SECURITY IN WLAN
• OPEN : No security configured X
• WEP : Wired Equivalent privacy X
• WPA: Wi-Fi Protected Access
• WPA2: Advance Wi-Fi Protected Access

4. WIRELESS SECURITY STANDARDS

5. WPA2 OVERVIEW
• Wi-Fi Protected Access 2
•
Security standard developed by the Wi-Fi Alliance and is an
implementation of IEEE’s 802.11i
•
Uses Advance Encryption Standard (AES) protocol
• AES in Counter-Mode for encryption
• AES in Cipher Block Chaining-Message Authentication Code (CBC-MAC)
for integrity checking

6. WI-FI PROTECTED ACCESS 2
Table: two types of WPA2

7. COMPARING WEP, WPA ,and WPA 2

8. AUTHENTICATION
Two types of authentication
• Personal mode
• Enterprise mode

9. PERSONAL MODE AUTHENTICATION
•
Authentication performed between
client and access point
•
PSK(Pre Shared Key) &
SSID(Service Set Identification) is
used
•
AP generates 256 bit from plain text
pass phrase
•
PMK(Pairwise Master Key) is
generated after authentication

10. ENTERPRISE MODE AUTHENTICATION
•
•
Based on IEEE 802.1x standard
Authentication performed between
:-
1. Client
2. Access Point
3. Authentication Server
• After authentication MK(Master
Key)
Is generated

11. WPA 2 KEY GENERATION
• 4 way handshake initiated by AP
• Confirms client’s knowledge of
PMK in personal mode & MK in
enterprise mode
• Pairwise Transient Key created
at client’s
• Fresh PTK is derived at AP
1. Key confirmation key
2. Key encryption key
3. Temporal key

12. WPA 2 KEY GENERATION
• Install encryption and integrity
key
• Control port are unblocked

13. WPA2 ENCRYPTION
• Two Process happens
1. Data encryption
2. Data integrity
• AES is used in encryption & authentication is a block symmetric cipher
• CCM is new mode of operation for block cipher
• Two underlying modes of CCM
 Counter mode(CTR) achieves data encryption
 Cipher block chaining message authentication code(CBCMAC) to provide data
integrity

14. MESSAGE INTEGRITY CODE(MIC)
• IV(Initialization Vector) encrypted
with AES & TK to produce 128
bit result
• 128 bit result is XOR with next
128 bits of data
• Result of XOR is continued until
all IV are exhausted
• At end,first 64 bits are used to
produce MIC
Figure :AES CBC-MAC

15. WPA2 ENCRYPTION
• Counter mode algorithm encrypts
the data with MIC
• Initialize counter for first time or
increment counter.
• First 128 bits are encrypted using
AES & TK to produce 128 bits.
• XOR is performed on result and first
message block to give an first
encrypted block.
• Repeat until all 128 bit of blocks has
been encrypted.
Figure: AES counter mode

16. WPA2 DECRYPTION
• It works in reverse using same algorithm for encryption the counter
value is derived.
• By using the counter mode algorithm and TK , the
MIC and decrypted
data are found out.
• The data is processed by CBC-MAC to recalculate MIC
• If MIC does not match then packet is dropped otherwise data is sent
to network stack and to client

17. BENEFITS OF WPA2
• Provides solid wireless security model(RSN)
• Encryption accomplished by a block cipher
• Block cipher used is Advanced Encryption Standard (AES)
• IEEE 802.11i authentication and key management is accomplished by
IEEE 802.1x standard
• Key-caching
• Pre-authentication

18. WPA2 VULNERABILITIES
 Can’t stand in front of the physical layer attacks:
RF jamming
Data flooding
Access points failure
 Vulnerable to the Mac addresses spoofing

19. PROCEDURES TO IMPROVE WIRELESS
SECURITY
 Use wireless intrusion prevention system (WIPS)
 Enable WPA-PSK
 Use a good passphrase
 Use WPA2 where possible
 Change your SSID every so often
 Wireless network users should use or upgrade their network to the
latest security standard released

20. FUTURE SCOPE
• A new standard IEEE 802.1W task group(TG) approved in
March,2005
 Main Goals
Improve security by protecting the management frames and also being able to
identify
Spoofed management frames normally used to launch DoS attack

21. THANK YOU!

22. REFRENCES
• “Benefits and Vulnerabilities of Wi-Fi Protected Access 2 (WPA2)”
Paul
By
Arana
• “The Evolution of 802.11 Wireless Security” INF 795 - Kevin Benton
• “Wireless LAN Security Issues and Solutions” by Pan Feng at 2012
IEEE Symposium on Robotics and Applications(ISRA)
• Security Improvements of
IEEE 802.11i 4-way Handshake Scheme
by Xiaodong Zha and Maode Ma ©2010 IEEE