Optical stateful security filtering approach based on code words

In this paper, we propose a stateful optical filtering approach that allows session establishment and traffic flow filtering in the optical layer. Each traffic flow is identified by a unique identifier composed of a set of code words built on values of appropriately selected fields in the stream. In the firewall core node, a security policy is applied to the optical flow based on its identifier in order to accept or reject the session establishment or the traffic data. The optical security policy is formed by a set of filtering rules which filters optical data units based on their traffic identifiers and implemented optically based on the optical logic gates. The proposed approach is based on two main components. The first component is an encoder used in the edge node, which generates traffic flow identifiers. And, the second component allows the stateful optical filtering implemented in the firewall node and divided into two modules: a stateful and a stateless filtering modules.