Image Number 9 for United States Patent #8086872.
Provided is a method for setting a security channel between an OLT and at least one ONU in an EPON. In detail, a channel is generated by which the OLT makes a reciprocal security capability agreement with the ONU that wants to set a security channel in a discovery interval and then automatically registers the ONU with the security capability agreement. The security channel is set by which the OLT distributes an encryption key for the security with the ONU completed with the security capability agreement. A renewal point of the encryption key is shared by transmitting a message indicative of a time to change the encryption key between the OLT and the ONU both completed with the encryption key distribution.