WIRELESS NETWORK SECURITY

1. WIRELESS NETWORK SECURITY

2. Hackers • Ad-hoc networks • War Driving • Man-in-the-Middle • Caffe Latte attack

3. AD-HOC networks

4. WAR DRIVING • Searching for Wi-Fi by person in moving vehicle

5. MAN-IN-THE-MIDDLE • Hotspots have little security • Entices computers to log into soft Access Point • Hacker connects to real AP – offers steady flow of traffic • Hacker sniffs the traffic • Forces you to loose connection + reconnect within the hackers AP.

6. CAFFE LATTE ATTACK • Targets the Windows wireless stack • Possible to obtain the WEP key from a remote client • Sends flood of encrypted ARP requests • Attacker can obtain the WEP key within minutes

7. Wireless Intrusion Prevention System (WIPS) • Robust way to counteract wireless security risks • PCI Security Standard Council published guidelines for large organizations

8. WEP: Wired Equivalent Privacy 1999 • Secret Keys [Codes to Encrypt Data] • Secondary Goal : Control Network Access

9. WEP • 64,128, 256 bit key • 24 bits used for Initialization Vector • Each packet includes integrity check

10. Stream Ciphers • RC4 is a stream cipher • Expands a key into an infinite pseudo-random keystream

11. What about IVs? • RC4 keystream should not be reused. • Use initialization vector to generate different keystream for each packet by augmenting the key • IV reuse(24 bits)=>16.7 million variations • Same shared key in both directions • Encryption is vulnerable to collision-based attacks.

12. Linear Checksum • Encrypted CRC-32 used as integrity check • Fine for random errors, but not deliberate ones • CRC is linear • Can maliciously flip bits in the packet • Can replay modified packets!

13. WEP • Problem #1: • No Limit on using the same IV Value more than once. This makes the encryption vulnerable to collision-based attacks. • Problem #2 • The IV is only 24 bits, there are only 16.7 million possible variations.

14. WEP • Problem: #3: • Master Keys are used directly, when they should be used to generate other temporary keys. • Problem #4: • Users don’t change their keys very often on most networks, giving attackers ample time to try various techniques.

15. 802.11i • TKIP [Temporal Key Integrity Protocol] • AES is a cryptographic algorithm - new hardware may be required • 802.1X: used for authentication

16. 802.1X • Keeps the network port disconnected until authentication is complete. • The port is either made available or the user is denied access to the network.

17. WPA: Wifi Protected Access • Subset of 802.11i • Master keys are never directly used. • Better key management. • Impressive message integrity checking.

18. WPA: Wifi Protected Access • Advantages: • IV length has increased to 48 bits, over 500 trillion possible key combinations • IVs better protected through the use of TKIP sequence counter, helping to prevents reuse of IV keys.

19. WPA: Wifi Protected Access • Master keys are never directly used • Better key management • Impressive message integrity checking.

20. 802.11i WPA2 • WPA2 uses AES (Advanced Encryption Standard) to provide stronger encryption. • Enterprise uses IEEE 802.1X and EAP to provide authentication. Consumer uses a pre-shared key, or password. • New session Keys for every association- unique to that client. • Avoids reuse.

21. WPA = TKIP + 802.1X To get a Robust Secure Network, the hardware must use CCMP [Counter Mode CBC MAC Protocol] WPA2 = CCMP+802.1X

22. TIPS • Change default Administrator Passwords for router. • Turn on WPA/WEP Encryption • Change the Default SSID • Enable Mac Address Filtering

23. TIPS • Disable SSID Broadcast • Do Not Auto-Connect to Open Wi-Fi Networks • Assign Static IP Addresses to Devices Turn off DHCP on the router access point

24. TIPS Ensure firewall is enabled on your router and also each computer connected.

25. TIPS • Position the router or Access Point Safely • Turn Off the Network during Extended Periods of Non-Use.

26. Questions ?