Ethical Hacking - NETWORK PENETRATION TESTING(7)

Gaining Access to encrypted networks

Three main encryption types:

1. WEP

2.WPA

3.WPA2

WEP Cracking

WEP is old encryption, but it is still used in some networks, therefore we will explain how to break it.

It uses an algorithm called RC4 where each packet is encrypted at the AP and is then decrypted at the client, WEP ensures that each packet has a unique keystream by using a random 24-bit Initializing Vector(IV), this IV is contained in the packets as plain text. The short IV means in a busy network we can collect more than two packets with the same IV, then we can use aircrack-ng to determine the keystream and the WEP key using statistical attacks.

Conclusion: The more IV's that we collect the more likely for us to crack the key.