A communication system generates a Master Session Key (MSK) for accesses to a system entity that does not provide encryption to traffic. Both the home server and the user generate the same MSK. The MSK is used to generate encryption keys for traffic. In one embodiment the MSK is generated using a hashing function and information specific to the requestor. The home server determines the need to generate the MSK based on information contained in an access request message. Once generated, the MSK is provided to the system entity to enable the entity to encrypt communications.