This book will investigate a number of security protocols, which are used in wireless networks. Security protocols like Wired Equivalent Privacy (WEP), WEP2, Wi-Fi Protected Access (WPA) and WPA2, which are protocols that were mainly developed to work within the IEEE 802.11 standard. Analysis of the protocols advantages and disadvantages will be introduced (vulnerabilities and problems), from the encryption and decryption point of view. A number of measures will be proposed to counter most of the known vulnerabilities that face the wireless networks security today. The countermeasures will be introduced in the form of a proposed security protocol, which will be called Multiple Slot System (MSS). A number of tests (mathematical and computer simulations) were carried out to prove the new protocol ability to provide at least a better security capabilities than the contemporary wireless LAN security protocols. The proposed measures can be used in a number of security related fields not just for LAN.