In this article, we analyze an authentication protocol, compatible with Global System for Mobile (GSM) communication, that employs an additional one way function to establish trust between a Mobile Unit and Visiting Location Register for the purpose of non-repudiation of service. The security of this protocol is discussed and a traffic analysis is performed indicating that the protocol’s message overhead during call origination is tolerable under various cell densities and traversal rates. The message penalty for use of the additional one way function is under 15% of total control traffic at vehicular speeds with an origination rate of 5.6 calls per handset per hour. The penalty for pedestrian traffic and high origination rate is about 23% of total control traffic. Therefore, the enhanced protocol appears undesirable for pedestrian networks unless the potential for fraud is great. However, the more modest overhead associated with vehicular traffic is acceptable when billing accuracy and service settlement is required between Personal Communications Networks.