Patent ID: 8838972

Claim:
A method for arranging security for a communications network, the method comprising: receiving session context information at an access node; extracting, at the access node using a processor, a session key from the session context information, wherein the session key is based upon a root key that is shared by a mobile terminal and a security node; decrypting, at the access node, the session key with a key associated with a security association between the access node and the security node of a communications network; encrypting, at the access node, at least part of a message with the session key for transmission of the message to the mobile terminal; receiving a common session protection key at the access node; decrypting the common session protection key with the key associated with the security association between the access node and the security node of the communications network; and decrypting at least a part of another message received from another access node with the common session protection key.