Which encryption standard for wireless networks was compromised by packet capture-based key cracking?

Which encryption standard for wireless networks was compromised by packet capture-based key cracking?

• A. WEP
• B. WPA
• C. WPA2
• D. WPA3

Answer: (A)

Weak IV handling in WEP makes it highly susceptible to packet-capture-based key cracking. WEP uses RC4 with a 24-bit initialization vector appended to each packet, and that IV is sent in the clear. Because the IV space is only 2^24, IV values collide frequently as you collect traffic, so an attacker who passively sniffs enough frames can link ciphertext to likely keystream values. By applying established attacks (like FMS and its refinements), the attacker can recover the RC4 keystream and ultimately deduce the shared WEP key. Once the key is known, all traffic can be decrypted. WPA and WPA2 introduce per-packet keys and stronger ciphers (TKIP and AES-CCMP), which resist this kind of passive, packet-capture key cracking, and WPA3 tightens security further. So the network standard compromised by this specific packet-capture approach is WEP.

Weak IV handling in WEP makes it highly susceptible to packet-capture-based key cracking. WEP uses RC4 with a 24-bit initialization vector appended to each packet, and that IV is sent in the clear. Because the IV space is only 2^24, IV values collide frequently as you collect traffic, so an attacker who passively sniffs enough frames can link ciphertext to likely keystream values. By applying established attacks (like FMS and its refinements), the attacker can recover the RC4 keystream and ultimately deduce the shared WEP key. Once the key is known, all traffic can be decrypted. WPA and WPA2 introduce per-packet keys and stronger ciphers (TKIP and AES-CCMP), which resist this kind of passive, packet-capture key cracking, and WPA3 tightens security further. So the network standard compromised by this specific packet-capture approach is WEP.