volume | PIER Journals

Abstract

Computer keyboards are often used to transmit confidential data such as passwords. The sensitive information such as keystrokes could be recovered by using the electromagnetic (EM) waves from the electronic components of the keyboard. In this paper, we have investigated the information leakage on the ground line of the PS/2 serial cable due to crosstalk and radiative coupling. The coupling principles are analyzed firstly. And then, through the experiments we found that the signals of keystrokes could leak to the ground line network which could then be detected on the other power outlets whose share the same electric line. Lastly, the eavesdropping experiments demonstrated that the keystrokes could be reproduced on the other places of the ground line network with no trace.

1. CISPR 22-Edition 5.2 "Information technology equipment-radio disturbance characteristics-limits and methods of measurement,", International Electro-technical Commission (IEC), 2006.
doi:10.1109/TEMC.2010.2103562 Google Scholar

2. Tosaka, T., Y. Yamanaka, and K. Fukunaga, "Method for determining whether or not information is contained in electromagnetic disturbance radiated from a PC display," IEEE Transactions on Electromagnetic Compatibility, Vol. 53, No. 2, 318-324, 2011. Google Scholar

3. Kuhn, M. G., "Compromising emanations: Eavesdropping risks of computer displays,", Technical Report 577, Computer Laboratory, University of Cambridge, 2003.
doi:10.1016/0167-4048(85)90046-X Google Scholar

4. Van Eck, W., "Electromagnetic radiation from video display units: An eavesdropping risk?," Computers & Security, Vol. 4, No. 4, 269-286, 1985.
doi:10.2528/PIERC09030907 Google Scholar

5. Sekiguchi, H. and S. Seto, "Measurement of computer RGB signals in conducted emission on power leads," Progress In Electromagnetics Research C, Vol. 7, 51-64, 2009. Google Scholar

6. Du, Y. L., Y. H. Lu, F. Mo, and N. Zhang, "A method for choosing the best frequency range for receiving the electromagnetic compromising emanations from a PC display," Journal of Beijing University of Posts and Telecommunications, Vol. 36, No. 1, 54-58, 2013. Google Scholar

7. Du, Y. L., Y. H. Lu, J. L. Zhang, and Q. Cui, "Estimation of eavesdropping distance from conducted emission on network cable of a PC," 2012 6th Asia-Pacific Conference on Environmental Electromagnetics (CEEM), 347-350, Beijing, China, Nov. 6-9, 2012. Google Scholar

8. Hayashi, Y. I., N. Homma, T. Mizuki, et al. "Efficient evaluation of EM radiation associated with information leakage from cryptographic devices," IEEE Transactions on Electromagnetic Compatibility, Vol. 55, No. 99, 1-9, 2012. Google Scholar

9. Vuagnoux, M. and S. Pasini, "Compromising electromagnetic emanations of wired and wireless keyboards," The 18th USENIX Security Symposium, 1-16, 2009. Google Scholar

10. Vuagnoux, M. and S. Pasini, "An improved technique to discover compromising electromagnetic emanations," Proc. 2010 IEEE Int. Symp. EMC, Florida, USA, Jul. 2010. Google Scholar

11. Wang, L. T. and B. Yu, "Research on the compromising electromagnetic emanations of PS/2 keyboard," Proceedings of the 2012 International Conference on Communication, Electronics and Automation Engineering, 23-29, Springer, Berlin, Heidelberg, 2013. Google Scholar

12. Backes, M., M. Durmuth, and D. Unruh, "Compromising reflections-or-how to read lcd monitors around the corner," IEEE Symposium on Security and Privacy (2008), 158-169, Oakland, CA, 2008. Google Scholar

13. Asonov, D. and R. Agrawal, "Keyboard acoustic emanations," Proceedings. 2004 IEEE Symposium on Security and Privacy, 3-11, IEEE Computer Society, May 9-12, 2004. Google Scholar

14. Berger, Y., A. Wool, and A. Yeredor, "Dictionary attacks using keyboard acoustic emanations," ACM Conference on Computer and Communications Security (2006), 245-254, New York, USA, 2006. Google Scholar

15. Zhang, L., F. Zhou, and J. D. Tygar, "Keyboard acoustic emanations revisited," ACM Conference on Computer and Communications Security (2005), 373-382, New York, USA, 2005. Google Scholar

16. Paul, C. R., Introduction to Electromagnetic Compatibility, Wiley, New York, 1992.
doi:10.1109/15.18789

17. Paul, C. R., "A comparison of the contribution of common-mode and differential-mode currents in radiated emission," IEEE Transactions on Electromagnetic Compatibility, Vol. 31, No. 2, 189-193, 1989. Google Scholar

Dr. Yu-Lei Du

Dr. Ying-Hua Lu

Dr. Jinling Zhang