  Network intrusion detection systems and antivirus software are essential in
detecting malicious network traffic and attacks such as denial-of-service and
malwares. Each attack, worm or virus has its own distinctive signature.
Signature-based intrusion detection and antivirus systems depend on pattern
matching to look for possible attack signatures. Pattern matching is a very
complex task, which requires a lot of time, memory and computing resources.
Software-based intrusion detection is not fast enough to match high network
speeds and the increasing number of attacks. In this paper, we propose special
purpose hardware for Wu-Manber pattern matching algorithm. FPGAs form an
excellent choice because of their massively parallel structure, reprogrammable
logic and memory resources. The hardware is designed in Verilog and implemented
using Xilinx ISE. For evaluation, we dope network traffic traces collected
using Wireshark with 2500 signatures from the ClamAV virus definitions
database. Experimental results show high speed that reaches up to 216 Mbps. In
addition, we evaluate time, device usage, and power consumption.
