In at least one embodiment, there is provided a mobile wireless device comprising: a microprocessor and memory, the memory comprising a set of control settings used to control a plurality of device operations; wherein the microprocessor is configured to: receive a first digital signature key for verifying digital signatures on software applications to be installed on the device; determine if any digital signature keys for verifying digital signatures on software applications to be installed on the device exist on the device, and if not, store the received first digital signature key in the memory; receive a software application for installation on the device; verify a digital signature on the received software application using the first digital signature key; and install the software application on the device if the digital signature on the received software application is successfully verified.