The present invention relates to a method and apparatus based on Bloom
filters for detecting predefined signatures (a string of bytes) in a
network packet payload. A Bloom filter is a data structure for
representing a set of strings in order to support membership queries.
Hardware Bloom filters isolate all packets that potentially contain
predefined signatures. Another independent process eliminates false
positives produced by the Bloom filters. The system is implemented on a
FPGA platform, resulting in a set of 10,000 strings being scanned in the
network data at the line speed of 2.4 Gbps.