Patent ID: 8644514

Claim:
A method comprising: acquiring a message to be transmitted to a mobile station via a relay station (RS); combining the message with a message authentication code (MsgAC) to form a combined message, wherein combining includes: determining if the relay station is configured to replace the MsgAC included by the combined message with a second MsgAC, and if so, generating the MsgAC based upon a MsgAC key (MsgACK) known to the RS; wherein the determining includes performing the following: if a message includes a user data type of message, causing the RS to be configured to replace the MsgAC of the combined message; and if the acquired message includes a MsgAC generated by an Intermediate MsgAC Key (IMsgACK), determining that an RS is allowed to manipulate portions of the message; and wirelessly transmitting the combined message to the RS.