Research On Filtering Technology Based On Content And Its Application In Gap

With the rapid development of Internet technology, it becomes more and more frequent that the non-trusted network exchanges information resource with trusted network. It is urgent to be solved the problem that how to ensure the information exchange security between trusted and non-trusted network, how to solve the network contradiction between opening and security. Then the appearance of Gap technology gives a solution to these problems of network security.The Gap provides technical sustain for secure isolation and information exchange between the non-trusted network and trusted network, and the mechanism of content checking is very important among the mechanisms of inner and outer network host computer. Thus the paper analyzes and studies two technologies firstly: content filtering and semantic analysis. Secondly, after researching the traditional content filtering model, it presents a composite mode filtering model based on content-combining the keywords matching and the semantic framework matching, constructs a composite mode filtering arithmetic based on content, and the performance testing of arithmetic shows that the precission and recall all receive a bigger improve. In the end, it appends the content filtering module into the NetFilter framework of the Gap, and implements the application of the composite mode filtering arithmetic based-on content in the Gap. The result of experiment indicates that the application of this arithmetic well resolves the illogicality of the real-time and the veracity of the network information filtering.In summary, the paper studies and researches the technology of content filtering in the Gap. The filtering arithmetic of composite mode based-on content designed has a good application in the Gap. The theoretical analysis and study in the paper and the realization technologies of the module of content filtering involved in the Gap system have important values for relative researches.