WPA-3: SEA and Dragonfly

1. WPA-3: SEA and
Dragonfly
Prof Bill Buchanan, The Cyber Academy
http://asecuritysite.com

2. Wireless Standards
• WEP: 40-bit encryption key. Stream cipher (RC4). 24-bit Initialisation
Vector. Single key for whole network. Bit flipping.
• WPA: Upgraded to TKIP. 128-bit key. Longer IV. Roll-over re-
negotiationof key.
• WPA-2 (IEEE 802.11i): Block cipher (AES). 4-way handshake.

3. Wireless
• A 24 bit Initialisation Vector (IV). This meant that the same encryption key
repeated after 2²⁴ data packets. This mean that an intruder just had to wait for the
IV value to return to a given value — typically within a few hours — and it was then
possible to crack the encryption key.
• A 40-bit encryption key. This meant which could be cracked with brute force.
Anything less than a 72-bit symmetric encryption key can typically be cracked on a
single computer. For example there are 2⁴⁰ keys, and which gives
1,099,511,627,776 different keys, and if we crack with 100 million keys per second,
we crack every key in around three hours.
• A global encryption for the network. WEP used a single global encryption key for
the network, thus anyone with secret key for the network could view all of the data
packets for the whole network.
• Lack of error checking. WEP lacked proper error checking, and which allowed bits
in the data packets to be flipped and still check a valid packet.

4. Four way handshake
• from pbkdf2 import PBKDF2
ssid = 'home'
phrase = 'qwerty123'
print "SSID: "+ssid
print "Pass phrase: "+phrase
print "Pairwise Master Key: " + PBKDF2(phrase, ssid,
4096).read(32).encode("hex"))
• A sample run is [here]:
• SSID: home
Pass phrase: qwerty123
Pairwise Master Key:
bbaf585c301dc4d4024523535f42baf04630f852e2b01979ec0401ed
cdf
0e9c8

5. WPA-2 Weaknesses
• Single capture of 4-way handshake and then off-line dictionary/brute
force.
• Off-line crack of hash of SSID and password.
• Single crack, cracks all other keys. No forward secrecy (FS).

6. WPA-3
• WPA3-Personal: This replaces the 4-way handshake with Simultaneous
Authentication of Equals (SAE) and which is defined in the IEEE
802.11s standard. SAE was initially defined for mesh networks, but is
now scaling to infrastructure wireless networks.
• WPA3-Enterprise: This integrates a back-end authentication
infrastructure, such as with a RADIUS server. Elliptic Curve Diffie-
Hellman (ECDH) exchange and Elliptic Curve Digital Signature Algorithm
(ECDSA) using a 384-bit elliptic curve are used to a strong
authentication.
• WPA-3 brings the integration of QR codes to gain the network
connection details.

7. SEA/Dragonfly: COMMIT
Code

8. SEA/Dragonfly: CONFIRM

9. Conclusions
• WPA-2 is flawed, and is not really fit for purpose.
• Our core protection is built around something that — given time — can be
cracked. As GPUs and ASIC advance we need to move away from hashed
passwords, as they are fundamentally flawed, and implement zero-
knowledge proof methods.
• A user should not be asked to show their password, but should be asked if
they can prove that they know it.
• Hashed passwords are typically the weak point in data breaches, and where
millions, if not billions (as in the case of Yahoo) can be released into the wild,
and where hackers can easily pick-off the passwords that users have used.
• Zero-knowledge proof is the future.

10. WPA-3: SEA and
Dragonfly
Prof Bill Buchanan, The Cyber Academy
http://asecuritysite.com