A system and method are disclosed that overcome deficiencies of prior art IEEE 802.11 WEP key management schemes. Preferred embodiments of the present system and method update WEP keys and rotate transmission key indices in a synchronized manner and on a frequent basis making it impractical for a hacker to gather sufficient network traffic using any one WEP key to decrypt that key and without disrupting communications. Preferred embodiments of the present system and method do not require changes in access point or mobile unit hardware, radio drivers, or firmware and are therefore compatible with existing or legacy network infrastructure or components. The disclosed system and method may be used to facilitate secure communications between one or more access points and one or more mobile units and/or groups of two or more mobile units engaging in peer-to-peer associations.