Wireless networks are becoming ubiquitous and can be found in domestic, commercial, industrial, military, and health care applications. One application of particular interest is that of emergency communications where an Incident Area Network (IAN) can be rapidly deployed at an incident site. Wireless networks are well suited to such applications because they can be rapidly established and facilitate the exchange of voice, video and multimedia content such as detailed maps, building plans and photographs. The experience of Hurricane Katrina, the Asian Tsunami and Black Saturday demonstrates the importance of effective communications in saving lives following a catastrophic event. The security of an emergency communications network is extremely important because a breach of confidentiality, integrity or availability may result in the loss of human life. Ensuring security presents a thorny problem because communication in a wireless network uses a shared medium without the benefit of a physical security perimeter. To address this problem wireless security protocols use cryptographic techniques to protect the network but the results have not always been successful. Serious flaws have been discovered in the design, implementation and operation of widely deployed wireless security protocols and attacks developed to exploit these flaws. Our investigation adopts the viewpoint of a hostile adversary to identify and exploit vulnerabilities that remain in wireless security protocols. Purpose-written software tools have been created to facilitate the investigation, conduct attacks and assist in the identification of the underlying causes of the security flaws. Remedial measures are then proposed, implemented and evaluated for the most serious threats.