As wireless networks are finally coming of age, people and organizations start to implement critical applications and infrastructures based on them. As most wireless network standards have been designed with security as an afterthought, severe security shortcomings were the results and several improvements and amendments were necessary to fix the worst. Founded on a series of insecure implementations and design faults, recent standards and amendments show some improvements. To cover personal area, local area and wide area wireless networks, the following standards have been chosen as examples: IEEE 802.15.1 Bluetooth, IEEE 802.11 WiFi and IEEE 802.16 WiMAX. This article provides a detailed overview, analysis and discussion of state-of-the-art security mechanisms in wireless networks and briefly presents their development and history allowing the reader to quickly gain detailed insight into the topic.