Research On The Leakage Mechanism Of Computer Information On Power Line

The electromagnetic radiation generated by computer equipment during operation not only pollutes the electromagnetic environment,but also causes the electromagnetic leakage of useful information and poses a threat to information security.At the same time,the electromagnetic information leaked by the computer can be transmitted outside through the power line,which has the characteristics of long-distance transmission,high channel capacity and wide coverage,which leads to an increase in the risk of information leakage.Therefore,the research on the mechanism and protection methods of computer information leakage is of great significance.This thesis has carried out in-depth research around the two main lines of computer leakage mechanism and protection methods.The study of leakage mechanism is carried out from three aspects of the leakage source,the leakage path and the leakage scope.Firstly,the computer information leakage source is analyzed by the research method which combines the theoretical analysis and the actual test.Then,based on the electromagnetic topology theory,the leakage information transmission method is explored.Finally,aiming at the problem of long-distance transmission of leakage information on power line,the power line channel is modeled and simulated.Combined with experimental tests,the leakage distance of the computer information on the power line is estimated.On this basis,the leakage information protection method is explored,and a passive filter is designed to protect the power line leakage information.The experiment verifies that the filter can effectively suppress the leakage signal.The following is the main work of this thesis:In the first part,combined with the characteristic of red signal leakage,the red signal is classified by taking the computer system as the object.By studying the working principle of computer components and conducting conduction test and near-field test on each component of the computer,the characteristics of the leakage source of each computer component are analyzed.In the second part,based on the basic principle of electromagnetic leakage and combined with the computer system composition and the signal flow,the computer system topology correlation diagram and the interference sequence diagram are established,and the ways of coupling leakage information to power line are analyzed.Through the simulation of the coupling way,the factors that affect the electromagnetic coupling amount are investigated.In the third part,aiming at the problem of the transmission of leakage information on the power line,a power line model based on a two-port network is established.Through simulation and testing,the influence of the power line topology on the power line loss is explored,and the relationship between the power line topology and transmission characteristics is investigated.Next,the conducted leakage distance of power line is estimated by testing.In the fourth part,the methods to suppress information leakage on power lines are explored.Firstly,the commonly used methods of information leakage prevention are analyzed.Combined with the characteristics of the information leakage on the power line,the design scheme of using passive filter plug-in strips to protect the information leakage on the power line is determined.Then the high-frequency parameters of the components are obtained through testing,and a simulation circuit of the simulated filter is built to simulate and analyze the insertion loss of the filter,which proves the performance of the filter in theory.Finally,the actual processing and performance verification of the filter are carried out.The experimental results show that the filter has a good suppression effect on the propagation of leakage information on the power line.