Apparatus and method for transitioning from a serving network node that supports an enhanced security context to a legacy serving network node

A remote station, comprising:

• means for providing at least one legacy key associated with a second security context, wherein a first security context of a current serving network node includes a security property that is not supported by the second security context;
• means for generating at least one session key, in accordance with the first security context, based on an information element associated with the first security context;
• means for forwarding a first message to a new serving network node, wherein the first message includes the information element signaling associated with the first security context;
• means for receiving, in response to the first message, a second message from the new serving network node, wherein the second message has a response based on either the at least one legacy key or the at least one session key;
• means for determining that the new serving network node does not support the first security context if the response of the second message is based on the at least one legacy key;
• and
• means for protecting communications based on the at least one legacy key upon determining that the new serving network node does not support the first security context.

A remote station, comprising:

• a processor configured to:
• provide at least one legacy key associated with a second security context, wherein a first security context of a current serving network node includes a security property that is not supported by the second security context;
• generate at least one session key, in accordance with the first security context, based on the legacy key and an information element associated with the first security context;
• forward a first message to a new serving network node, wherein the first message includes the information element associated with the first security context;
• receive, in response to the first message, a second message from the new serving network node, wherein the second message has a response based on either the at least one legacy key or the at least one session key;
• determine that the new serving network node does not support the first security context if the response of the second message is based on the at least one legacy key;
• and
• protect communications based on the at least one legacy key upon determining that the new serving network node does not support the first security context.

A computer program product, comprising:

• computer-readable storage medium, comprising:
• code for causing a computer to provide at least one legacy key associated with a second security context, wherein a first security context of a current serving network node includes a security property that is not supported by the second security context;
• code for causing a computer to generate at least one session key, in accordance with the first security context, based on an information element associated with the first security context;
• code for causing a computer to forward a first message to a new serving network node, wherein the first message includes the information element associated with the first security context;
• code for causing a computer to receive, in response to the first message, a second message from the new serving network node, wherein the second message has a response based on either the at least one legacy key or the at least one session key;
• code for causing a computer to determine that the new serving network node does not support the first security context if the response of the second message is based on the at least one legacy key;
• and
• code for causing a computer to protect communications based on the at least one legacy key upon determining that the new serving network node does not support the first security context.