Wireless networks provide vulnerable gateways for unauthorised entry to networks or even a standalone wireless computer. The independent radio signals that constitute wireless communications have no physical boundary to keep them in check. This allows a third party to easily eavesdrop on communications sessions and by capturing the data packets, they can break the encryption keys and access the data within the network. The public awareness of the insecurity of wireless networks is surprisingly poor despite frequent news media reports of the vulnerabilities of the equipment and the activities of the criminals prepare to exploit it. In this paper we review the security protocols commonly used on wireless networks and investigate their weaknesses by showing how easy it is to crack the codes using tools freely available on the Internet.