Research Of IDS Detection Model Based On Sampling Policy

This paper analyses arithmetic and implement of two main kinds of IDS, and has bring forward a new kind of IDS data collector model and we also did some test to verify this model. For the convenience of the construction of the model , we first define the basic concept which are need by the defination, then we use sampling technology and probability theory and use the math expectation formula to deduce the math model of simple equation probability random sampling, prove and simplify the math model we have made, On this base, we extend the math model of equation probability simple random sampling and troop sampling. This model is the math base of our data collector. This paper still makes some research on the error range when using this model to carry on data collection and calculates various kinds of probability parameter. This paper has made a determination the nature and ration discuss, and give the computing formula to compute the number which the detection need. The formula has two branch: first, the attack traffice is the big portion of all the traffic, we can adopt equal probability model to measure the sampling traffic according to the requirement for measuring the precision. Second, the attack traffice is the small portion of all the traffic, we can use the rare event model to compute the number. With the proof of experiment, the math model by the text which constructed is effective.