Patent ID: 7724899

Claim:
A method for controlling a security channel in a MAC security service network performing an encoding of transmitting/receiving frame using a parameter including a security association key and an initialization vector, comprising the steps of: configuring at least one processor to perform the functions of: a) sharing an upper bit initial value of an initialization vector of an encryption algorithm and a predetermined using range thereof between a transmitting side and a receiving side when a security channel is created; b) creating a secure association between a transmitting side and a receiving side by setting an association number, a next packet number which is a lower bit value of the initialization vector, and a secure association key; c) changing a packet number whenever a frame is transmitted until all of predetermined packet numbers are used; and d) changing the upper bit value of the initialization vector when all of the predetermined packet numbers are used so as to extend a life time of said secure association key, wherein the initialization vector dose not have an identical value within a same security association key, and performing the step b).