2.2 - Wireless Encryption

Question 1

Securing a wireless network

Answer 1

• An organization’s wireless network can contain
  confidential information
  – Not everyone is allowed access
• Authenticate the users before granting access
  – Who gets access to the wireless network?
  – Username, password, multi-factor authentication
• Ensure that all communication is confidential
  – Encrypt the wireless data
• Verify the integrity of all communication
  – The received data should be identical to
  the original sent data
  – A message integrity check (MIC)

Question 2

WPA (Wi-Fi Protected Access)

Answer 2

• 2002: WPA was the replacement for serious
  cryptographic weaknesses in
  WEP (Wired Equivalent Privacy)
  – Don’t use WEP
• Needed a short-term bridge between WEP and
  whatever would be the successor
  – Run on existing hardware

Question 3

Wireless encryption

Answer 3

• All wireless computers are
  radio transmitters and receivers
  – Anyone can listen in
• Solution: Encrypt the data
  – Everyone has an encryption key
• Only people with the right key can transmit and listen
  – WPA2 and WPA3

Question 4

WPA2 and CCMP

Answer 4

• Wi-Fi Protected Access II (WPA2)
  – WPA2 certification began in 2004
• CCMP block cipher mode
  – Counter Mode with Cipher Block Chaining Message
  Authentication Code Protocol, or
  Counter/CBC-MAC Protocol
• CCMP security services
  – Data confidentiality with AES encryption
  – Message Integrity Check (MIC) with CBC-MAC

Question 5

WPA3 and GCMP

Answer 5

• Wi-Fi Protected Access 3 (WPA3)
  – Introduced in 2018
• GCMP block cipher mode
  – Galois/Counter Mode Protocol
  – A stronger encryption than WPA2
• GCMP security services
  – Data confidentiality with AES
  – Message Integrity Check (MIC) with
  – Galois Message Authentication Code (GMAC)

Question 6

The WPA2 PSK problem

Answer 6

• WPA2 has a PSK brute-force problem
  – Listen to the four-way handshake
  – Some methods can derive the PSK hash
  without the handshake
  – Capture the hash
• With the hash, attackers can brute force the
  pre-shared key (PSK)
• This has become easier as technology improves
  – A weak PSK is easier to brute force
  – GPU processing speeds
  – Cloud-based password cracking
• Once you have the PSK, you have everyone’s
  wireless key

Question 7

SAE

Answer 7

• WPA3 changes the PSK authentication process
  – Includes mutual authentication
  – Creates a shared session key without sending
  that key across the network
  – No more four-way handshakes, no hashes,
  no brute force attacks
• Simultaneous Authentication of Equals (SAE)
  – A Diffie-Hellman derived key exchange with
  an authentication component
  – Everyone uses a different session key, even with
  the same PSK
  – An IEEE standard - the dragonfly handshake

Question 8

Wireless security modes

Answer 8

• Configure the authentication on your
  wireless access point / wireless router
• Open System
  – No authentication password is required
• WPA/2/3-Personal / WPA/2/3-PSK
  – WPA2 or WPA3 with a pre-shared key
  – Everyone uses the same 256-bit key
• WPA/2/3-Enterprise / WPA/2/3-802.1X
  – Authenticates users individually with an
  authentication server (i.e., RADIUS)