Date Added: Feb 2010
Multi-pattern matching is a key technique for implementing network security applications such as Network Intrusion Detection/Protection Systems (NIDS/NIPSes) where every packet is inspected against predefined attack signatures written in regular expressions (regexes). To this end, Deterministic Finite Automaton (DFA) is widely used for multi-regex matching, but existing DFA-based research have claimed high throughput at an expense of extremely high memory cost. In this paper, the authors propose a parallel architecture of DFA called Parallel DFA (PDFA), using multiple flow aggregations to increase the throughput with nearly no extra memory cost. The basic idea is to selectively store the DFA in multiple memory modules which can be accessed in parallel and to explore the potential parallelism.