High-throughput linked-pattern matching for intrusion detection systems

This paper presents a hardware architecture for highly efficient intrusion detection systems. In addition, a software tool for automatically generating the hardware is presented. Intrusion detection for network security is a compute-intensive application demanding high system performance. By moving both the string matching and the linking of multi-part rules to hardware, our architecture leaves the host system free for higher-level analysis. The tool automates the creation of efficient field programmable gate array architectures (FPGA). The generated hardware allows an FPGA-based system to perform deep-packet inspection of streams at up to 10 Gb/s line rates at a high level of area efficiency. Going beyond previous basic string-matching implementations that offer only single-string matching, the architecture provides support for rules requiring complex, linked (correlated-content) constructions. This allows most Snort content-linking extensions including ´distance´ and ´within´ bounding restrictions.