Date Added: Feb 2011
Recent Network Intrusion Detection Systems (NIDSs) utilize Perl Compatible Regular Expression to describe malicious patterns existing in the content payload of packets more and more efficiently. Several techniques are introduced to optimize the performance or complete the system for full support all of PCRE features in hardware platform, but some issues have just been solved partially. Constraint Repetition is among important characteristics of PCRE but its effective hardware-based implementation solutions are still limited. This paper describes an Enhanced Constraint rEpetition Block (ECEB) for regular expression matching engine in FPGA.