Secure access by a mobile wireless terminal of a wireless telephony network is achieved by having a Home Location Register store the terminal's temporary and permanent identities. Upon accessing the network following initial registration, the terminal sends a temporary identity to a Serving GPRS Support Node (SGSN). If no serving node in the network knows the terminal, the terminal need not sent its permanent identity in clear as was previously required. Rather, the serving node need only query the HLR since the HLR can map the terminal's temporary identity to its permanent identity. In this way, the permanent identity of the mobile wireless terminal remains secure.