The existing theory and techniques of wireless communication anti-jamming have reached their performance limit recently.With this focus,by leveraging the inherent characteristics of wireless communication and referrin...The existing theory and techniques of wireless communication anti-jamming have reached their performance limit recently.With this focus,by leveraging the inherent characteristics of wireless communication and referring to the principle of cyberspace endogenous security,this paper investigates the core issues of endogenous security in the electromagnetic space,namely,endogenous anti-jamming(EAJ),which can defend against unknown electromagnetic attacks effectively.Specifically,the subspace method is first adopted to establish the unified framework for the conventional spread-spectrum,intelligent,and endogenous antijamming,in which both the intrinsic development law of each technique and the internal logic between them are revealed.Then,the fundamental concept,key techniques,and development suggestions of wireless communication“N+1 dimensionality”endogenous anti-jamming are proposed to seek a disruptive breakthrough.展开更多
The display image of the video display unit （VDU） can be reconstructed by receiving and analyzing the unexpected electromagnetic noise emanated from a personal computer system. This fact is one of the information le...The display image of the video display unit （VDU） can be reconstructed by receiving and analyzing the unexpected electromagnetic noise emanated from a personal computer system. This fact is one of the information leakage threats in information security. Therefore, in order to choose the best frequency range for receiving the electromagnetic compromising emanations form a PC display effectively and quickly, a method based on the correlation power analysis （CPA） and the common equipments is proposed. Firstly, the frequency spectrum of 10 MHz to 1 GHz is measured about 10 times respectively when the PC is displaying the white-black vertical strips image and black image. The frequency range which contains the display information can be obtained through the CPA. And then, the special image signal is searched around the dot frequency and harmonics. If the special signal disappears when displaying the total black image, it can be judged to be the real special signal. Finally, the best receiving frequency range can be chosen by comprehensive considering the results of CPA and the signal to noise ratio （SNR） of the special image signal. In order to check the validity of the chosen frequency range, eavesdropping experiments are carried out. The results demonstrate that the selected frequency range can retrieve the higher quality image than other frequency bands.展开更多
The display image of a PC can be reconstructed by using the conducted emission on the PC＇s network cable. The relevant signals which be used to reconstruct the original image are coupling from the radiation of the sw...The display image of a PC can be reconstructed by using the conducted emission on the PC＇s network cable. The relevant signals which be used to reconstruct the original image are coupling from the radiation of the switching of red, green, blue （RGB） signals in PC. These pertinent signals are partly contained in the frequency region higher than 30 MHz in the conducted emission. From these findings, the near-field coupling principle from PC to the network cable is analyzed firstly. And then, a multi-conductor transmission model for the RGB signals which transmit in the network cable is proposed. In addition, the maximum safe distance is estimated by using this model. In order to check the validity of the estimating distance, the eavesdropping experiment is carried out to reconstruct the original display image. The results demonstrate that the blurred display image can be retrieved at the place of 29.5 m.展开更多
文摘The existing theory and techniques of wireless communication anti-jamming have reached their performance limit recently.With this focus,by leveraging the inherent characteristics of wireless communication and referring to the principle of cyberspace endogenous security,this paper investigates the core issues of endogenous security in the electromagnetic space,namely,endogenous anti-jamming(EAJ),which can defend against unknown electromagnetic attacks effectively.Specifically,the subspace method is first adopted to establish the unified framework for the conventional spread-spectrum,intelligent,and endogenous antijamming,in which both the intrinsic development law of each technique and the internal logic between them are revealed.Then,the fundamental concept,key techniques,and development suggestions of wireless communication“N+1 dimensionality”endogenous anti-jamming are proposed to seek a disruptive breakthrough.
基金supported by the National Natural Science Foundation of China (61072136, 61171051)
文摘The display image of the video display unit （VDU） can be reconstructed by receiving and analyzing the unexpected electromagnetic noise emanated from a personal computer system. This fact is one of the information leakage threats in information security. Therefore, in order to choose the best frequency range for receiving the electromagnetic compromising emanations form a PC display effectively and quickly, a method based on the correlation power analysis （CPA） and the common equipments is proposed. Firstly, the frequency spectrum of 10 MHz to 1 GHz is measured about 10 times respectively when the PC is displaying the white-black vertical strips image and black image. The frequency range which contains the display information can be obtained through the CPA. And then, the special image signal is searched around the dot frequency and harmonics. If the special signal disappears when displaying the total black image, it can be judged to be the real special signal. Finally, the best receiving frequency range can be chosen by comprehensive considering the results of CPA and the signal to noise ratio （SNR） of the special image signal. In order to check the validity of the chosen frequency range, eavesdropping experiments are carried out. The results demonstrate that the selected frequency range can retrieve the higher quality image than other frequency bands.
基金supported by the National Natural Science Foundation of China (61072136, 61171051)
文摘The display image of a PC can be reconstructed by using the conducted emission on the PC＇s network cable. The relevant signals which be used to reconstruct the original image are coupling from the radiation of the switching of red, green, blue （RGB） signals in PC. These pertinent signals are partly contained in the frequency region higher than 30 MHz in the conducted emission. From these findings, the near-field coupling principle from PC to the network cable is analyzed firstly. And then, a multi-conductor transmission model for the RGB signals which transmit in the network cable is proposed. In addition, the maximum safe distance is estimated by using this model. In order to check the validity of the estimating distance, the eavesdropping experiment is carried out to reconstruct the original display image. The results demonstrate that the blurred display image can be retrieved at the place of 29.5 m.
