One feature pertains to a method operational at a device. The method includes performing key agreement with a core network device, and generating an authentication session key based in part on a secret key shared with a home subscriber server (HSS), where the authentication session key is known to the core network device. The method further includes generating a mobility session key based in part on the authentication session key, where the mobility session key is known to a mobility management entity (MME) served by the core network device and serving the device. The method also includes cryptographically securing data sent from the device to a wireless communication network using the mobility session key.