GIAC Certified Incident Handler (GCIH) Practice Exam

The key idea is that WEP’s design allows an attacker to recover the shared key just by listening to traffic. WEP uses RC4 with a 24-bit Initialization Vector that is sent in clear alongside the secret key. Because the IV space is small, the same keystream gets reused across many packets, which lets attackers perform statistical/bias-based analyses to uncover the RC4 key over time. Once the key is known, all encrypted traffic can be decrypted and even spoofed frames can be injected. So simply collecting enough captured packets enables key recovery, making WEP insecure. The other statements are inaccurate: WEP does not use RSA, does not rely on a 256-bit key by default, and VPNs are not what makes WEP secure.