EM alignment using phase for secure embedded systems


If electromagnetic (EM) waves emanating from a wireless device during a cryptographic computation leak sufficient information, it may be possible for an attacker to reconstruct the secret key. Despite the complexities of a Java-based PDA device, this paper presents a new phase based technique for aligning EM frames for subsequent time based DEMA. The proposed technique involves: fast Fourier transform, phase-substitution, inverse fast Fourier transform and time based DEMA. Results are repeatable over several different secret keys. Unlike previous research the new technique does not require perfect alignment of EM frames, and demonstrates robustness in the presence of a complex embedded system (including cache misses, operating system events, etc.) with random delays as well as random operations. This research is important for future wireless and complex embedded systems where security is crucial.

This is a preview of subscription content, access via your institution.


  1. 1.

    Kocher P, Jaffe J, Jun B (1999) Differential power analysis. In: Crypto’99. Lecture notes in computer science, vol 1666. Springer, Berlin, pp 388–397

    Google Scholar 

  2. 2.

    Brian Gladman Dr (2003) A specification for Rijndael, the AES algorithm, at fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf

  3. 3.

    Agrawal D et al (2002) The EM side-channel(s). In: CHES 2002, pp 29–45

  4. 4.

    Gandolfi K et al. (2001) Electromagnetic analysis: concrete results. In: CHES 2001. Lecture notes in computer science, vol 2162. Springer, Berlin, pp 251–261

    Google Scholar 

  5. 5.

    Agrawal D et al. The EM side-channel…methodologies. http://www.research.ibm.com/intsec/emf.html

  6. 6.

    Itoh K et al (2002) DPA countermeasure based on the masking method. In: Lecture notes in computer science, vol 2288. Springer, Berlin, pp 440–456

  7. 7.

    Messerges T (2000) Using 2nd order power analysis to attack DPA resistant software. In: Lecture notes in computer science, vol 1965. Springer, Berlin, pp 238–251

  8. 8.

    Ravi S et al (2002) Securing wireless data: system architecture challenges. In: ISSS, pp 195–200

  9. 9.

    Waddle J, Wagner D (2004) Towards efficient second-order power analysis. In: CHES 2004. Lecture notes in computer science, vol 3156. Springer, Berlin, pp 1–15

    Google Scholar 

  10. 10.

    Agrawal D et al. (2003) Advances in side-channel cryptanalysis EM analysis and template attacks. RSA Cryptobytes 16(1):20–32

    Google Scholar 

  11. 11.

    Agrawal D et al (2003) Power, EM and all that: is your crypto device really secure? In: Presentation ECC workshop. http://www.cacr.math.uwaterloo.ca/conferences/2003/ecc2003/rohatgi.ppt

  12. 12.

    Messerges T (2001) Securing the Rijndael finalists against power analysis attacks. In: Lecture notes in computer science, vol 1978. Springer, Berlin, pp 150–164

  13. 13.

    Gebotys C, Ho S, Tiu A (2005) EM analysis of Rijndael and ECC on a wireless Java-based PDA. In: Proceedings of CHES 2005. Lecture notes in computer science, vol 3659. Springer, Berlin, pp 250–265

    Google Scholar 

  14. 14.

    Homma N et al (2006) High-resolution side-channel attack using phase-based waveform matching. In: Proceedings of CHES 2006. Lecture notes in computer science. Springer, Berlin (to appear)

  15. 15.

    Quisquater J-J et al (2000) A new tool for non-intrusive analysis of smartcards based on EM emissions. In: Rump session, Eurocrypt

  16. 16.

    Brian Gladman Dr (2003) A specification for Rijndael, the AES algorithm. fp.gladman.plus.com/cryptography_technology/rijndael/aes.spec.311.pdf

  17. 17.

    Chari S et al (1999) Towards sound approaches to counteract power-analysis attacks. In: Lecture notes in computer science, vol 1666. Springer, Berlin, pp 398–412

  18. 18.

    Goubin L, Patarin J (2001) DES and differential power analysis—the duplication method. In: CHES, pp 158–172

  19. 19.

    Golic J (2002) Multiplicative masking and power analysis of Rijndael. In: CHES, pp 1–10

  20. 20.

    Oren Y, Shamir A. Power analysis of RFID tags. http://www.wisdom.weizmann.ac.il/~yossio/rfid2006

  21. 21.

    Gebotys C, White B (2006) Methodology for attack on a Java-based PDA. In: Proceedings of IEEE/ACM CODES+ISSS, Seoul, S. Korea, pp 94–99

  22. 22.

    Mangard S, Oswald E, Popp T (2007) Power analysis attacks revealing the secrets of smart cards. Springer, Berlin

    MATH  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Catherine Gebotys.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Gebotys, C., White, B.A. EM alignment using phase for secure embedded systems. Des Autom Embed Syst 12, 185–206 (2008). https://doi.org/10.1007/s10617-008-9016-0

Download citation


  • Side channel analysis
  • Security
  • Embedded systems
  • EM differential analysis
  • Smart cards
  • Java
  • Phase substitution