This document discusses network security techniques such as authentication and encryption. It provides an overview of 802.1X authentication, which authenticates network clients using unique client information and credentials known only to the client. MAC authentication bypass (MAB) is also discussed, which enables port-based access control using the MAC address of the connecting device. Common encryption techniques are examined, including WEP (outdated), WPA/TKIP, and WPA2/AES. Symmetric key encryption uses a shared secret key for encryption and decryption, while asymmetric encryption uses public/private key pairs.