Abstract: A method for controlling a security channel for reducing system load by extending the use period of a security association key is provided. In this method, an upper bit initial value of an initialization vector of an encryption algorithm and a using range thereof are shared between a transmitting side and a receiving side when a security channel is created. Then, a secure association is created between a transmitting side and a receiving side by setting an association number, a next packet number which is a lower bit value of an initialization vector, and a secure association key. Afterward, a packet number is modified whenever a frame is transmitted until all of packet numbers are used. When all packet numbers are used, the upper bit value of the initialization vector changes.

Abstract: Provided is a method of monitoring link performance and diagnosing an active link state without interrupting traffic in an Ethernet passive optical network (EPON) while the link is in the active state.

Abstract: An authentication method for link protection between an OLT and an ONU newly connected thereto in an EPON, which is implemented in a data link layer to which cryptography is applied. First, an authentication key is distributed to both the OLT and an ONU. The OLT (or ONU) generates first and second random values, generates an authentication request frame containing the random values, and transmits it to the ONU (or OLT). The ONU generates a first hash value according to a hash function using the random values contained in the request frame, and transmits an authentication response frame containing the first hash value to the OLT. The OLT compares the first hash value with a second hash value calculated by it according to the has function using the two random values and an authentication key distributed to it, and transmits an authentication result frame to the ONU.

Abstract: The present invention provides a method for detecting a security module for link protection in an EPON, wherein an OLT and an ONU in the EPON can check whether or not an encryption module is present in each other and check the configuration of each other in order to avoid loss of a message when the message is encrypted for link protection between the OLT and the ONU in the EPON.