One embodiment of the present invention is a method for 
processing data in a computer or computer communications network that includes the steps of analyzing data using at least a first 
Heuristic / Deterministic Finite Automata (H / DFA), to classify data based upon pre-programmed programmed classification values assigned to different possible input data and / or pre-trained or dynamically updated 
heuristic engine output, and to select data for further 
processing based upon the 
resultant classification values that the logically interconnected look-up tables and / or 
heuristic components output given the input data. This exemplary embodiment overcomes disadvantages of previous methods for providing 
access control list, firewall, intrusion detection, intrusion prevention, spam 
filtration, anti-spyware, anti-
phishing, anti-
virus, anti-trojan, anti-worm, other 
computer security, routing, and / or switching related functionality. 
Heuristic algorithms, or a combination of logically interconnected look-up tables and 
heuristic techniques can also implement the H / DFA functionality. There are significant advantages in speed and 
scalability.