Multi-Character Processor Array for Pattern Matching in Network Intrusion Detection System

Network intrusion detection system (NIDS) is a system developed for identifying attacks by using a set of rules. NIDS is an efficient way to provide the security protection for today's Internet. Pattern match algorithm plays an important role in NIDS that performs searches against multiple patterns for a string match. Pattern matching is a computationally expensive task. Traditional software-based NIDS solutions usually can not achieve a high-speed required for ever growing Internet attacks. In order to satisfy high-speed packet content inspection, hardware-implementable pattern match algorithm is required. In this paper, we propose a hardware-based pattern match architecture that employs a multi-character processor array. The proposed multi-character processor array is a parallel and pipelined architecture which can process multiple characters of the input stream per cycle. The proposed architecture can reduce a lot of unnecessary computations and thus it is power efficient. We use snort pattern sets and DEFCON packet traces to perform our simulations. Our experiment results show that, with a 3-character processor array, we can reduce 83% of the computations compared with the brute force approach.