WEP crack definition
A WEP crack is an attack that exploits vulnerabilities of the Wired Equivalent Privacy protocol. WEP was an early encryption method used to secure wireless networks. Several methods have been developed over the years to crack WEP because of its weak encryption keys.
The vulnerabilities in WEP led to the near-complete abandonment of the protocol in favor of more secure solutions, such as WPA2 and WPA3.
Examples of WEP cracks
- IV (Initialization Vector) attack. An attacker captures many encrypted packets and uses statistical techniques to guess the encryption key. The short length and predictability of the IV in WEP make this possible.
- FMS Attack. Named after Fluhrer, Mantin, and Shamir, who first identified the attack, the FMS attack targets weak IVs that lead to the revelation of significant information about the secret WEP key.
- KoreK Attacks. KoreK developed several improvements on the FMS attack, like reducing the number of IVs required to crack the WEP key.
- Chopchop Attack. Also known as the KoreK chopchop attack, it allows an attacker to decrypt a packet without knowing the key. By guessing each byte of the packet payload and checking the correctness of the guess by sending a packet and watching for a response, an attacker can iteratively determine each byte of the payload.
- Fragmentation Attack. If an attacker has found a packet with a weak IV, they can decrypt the rest of the packet to obtain the keystream. Since WEP reuses keystreams, the attacker can use this keystream to send their data.