A Parallel String Searching Algorithm for Information Filtering

Playing an increasingly important role in the security protection of the network information systems,the intrusion detection system(IDS) becomes a hotspot of research interest nowadays.However,this technology in the kernel to many of these systems,namely string searching algorithm,has not received enough attention.By utilizing the concurrent mechanisms(multi-threading) provided by modern operation systems,such work can be divided symmetrically and thus improve the throughput of the corresponding application effectively.Presented in this work is a paralleled string searching algorithm-PBM,an algorithm based on the famous Boyer-Moore(BM) string searching algorithm.Taken as a dividable process,the string searching work is distributed between many cooperating threads of execution in the PBM algorithm,while each of them searches the target pattern in their respective share of the target strings.As compared with the traditional string searching algorithms,the PBM algorithm can do the pattern matching work faster by increasing the data processing throughput,thus adapting better to the drastic increase in the network band width.A simplification of the PBM algorithm that can be used as a multi-string searching algorithm is also suggested with supporting simulations,which is a promising approach when the number of target patterns is limited.