Trojan Side-Channels

Establishing a hidden communication channel using side-channels.


In this project we examine ways to establish hidden communication channels in embedded systems using side-channels. Classic side-channel attacks exploit the fact that during the computation of an algorithm unintentional side-channels leak out information about the processed data. Typical side-channels are the power consumption of a device, the execution time or electromagnetic radiation. These side-channels are mostly used by attackers to retrieve a secret key of an encryption algorithm. A lot of research has focused on efficient side-channel attacks as well as on methods how these attacks can be prevented.

However, in this project we are looking at side-channels from another perspective. Instead of using unintentional side-channels, we look at how we can build intentional side-channels into embedded systems. By inserting "Trojan" hardware into a system we establish a hidden communication channel that we can use to secretly transmit information. As the name Trojan side-channels suggest, this can be used in a malicious way to build very small and lightweight hardware Trojans that can be very difficult to detect. However, Trojan side-channels can also be used in a constructive way. We show that the properties of the Trojan side-channels are very well suited to build robust and lightweight hardware watermarks. Furthermore, the idea of side-channel watermarks can also be extended from hardware implementation towards software to build side-channel based software watermarks for embedded systems.



  • [NEWCAS 2011] Georg T. Becker, Wayne Burleson, and Christof Paar.
    Side-channel Watermarks for Embedded Software. 9th IEEE NEWCAS Conference (NEWCAS 2011), Bordeaux, France, June 2011. , (PDF)
  • [HOST 2010] Georg T. Becker, Markus Kasper, Amir Moradi, and Christof Paar.
    Side-channel based watermarks for integrated circuits. IEEE International Symposium on Hardware-Oriented Security and Trust (HOST), 2010. , (PDF)
    Also presented at the Workshop on Secure Component and System Identification, SECSI 2010, and as an extendet abstract (PDF) at the First International Workshop on Constructive Side-Channel Analysis and Secure Design, COSADE 2010.
  • [CHES 2009] Lang Lin, Markus Kasper, T. GŁneysu, Christof Paar, and Wayne Burleson.
    Trojan Side-Channels: Lightweight Hardware Trojans through Side-Channel Engineering. International Workshop on Cryptographic Hardware and Embedded Systems (CHES) 2009. (PDF)


Any opinions, findings, and conclusions or recommendations expressed in these materials are those of the author(s) and do not necessarily reflect the views of the sponsors.