Research On Hardware Trojan Detection Technology Under Process Variation And Calibration Methods

Hardware Trojan is a kind of malicious tampering of the integrated circuit,and it will steal key information or disable the chip once activated.Thus it is one of the main safety problems in the field of integrated circuit design.And it is very difficult to be found by functional test due to its stealthy nature.Side channel and ring oscillator based hardware Trojan detection technology attracts much attention.However process variation may cover the impact of hardware Trojan and lead to the increase of difficulties in detecting algorithms.Process variation is one of the key issues in hardware Trojan detection technology.Based on the analysis of the influence of process variation on side channel and ring oscillator frequency,modeling of hardware Trojan detection is done.Firstly,for power side channel based hardware Trojan detection technology,by using Hspice Monte Carlo simulation based on 0.18 ?m technology,power side channel information under process variation is obtained by varying transistor parameters.And the impact of process variation on side channel is analyzed: process variation will lead to differences among the same circuits,and it is difficult to tell whether these differences are caused by process variation or hardware Trojan.In order to identify Trojans,maximum likelihood factor analysis based method is proposed to detect hardware Trojans.FPGA experimentation is done.Then by placing the same test circuit in different locations and test,power side channel information under process variation is obtained.When the original circuit is equivalent to about 4292 nand gates,this method can effectively detect hardware Trojan with an area ratio of about 0.44%.Considering ring oscillator(RO)based hardware Trojan detection method is also influenced by process variation,and it will increase the difficulty in detection method due to discreteness of the chip's oscillation frequency,research is done on this method.A systematic research is done on RO based hardware Trojan detection technology,and the impact of RO structure,number of stages,embed method and distance from the Trojan on Trojan detection is simulated.In order to reduce process variation's impact,the distinct response to the supply voltage of the HTs and process variations is experimentally analyzed.By changing supply voltage,proportion of the two in the test data is changed,and pairwise distance analysis method using Mahalanobis distance or Euclidean distance is applied to identify whether the circuit is Trojan infected.Using this method,the discreteness of RO frequency is reduced and Trojan can be successfully detected by simulation and FPGA experimentation.