By analyzing the influence on the reputation of sensornode’s report from the historical sensing results, the weightof reputation value should be updated with the varying of thesensing time. In order to ensure the robustness of the system,the model should have a certain tolerance for honest userswho occasionally send error sensing data, and its reputationvalue can be gradually improved by continuously reportingcorrect data in subsequent period. Let m denote the maximum storage length of the cognitive sensor node’s historicalevaluation value, and according to the historical evaluation value, the positive evaluation posi(k) and negative evaluationnegi(k) of cognitive sensor node i in the k-th sensing time slotcan be obtained by