Mode-based obfuscation using control-flow modifications

Sandhya Koteshwara, Chris H. Kim, Keshab K. Parhi

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Scopus citations


Hardware security has emerged as an important topic in the wake of increasing threats on integrated circuits which include reverse engineering, intellectual property (IP) piracy and overbuilding. This paper explores obfuscation of circuits as a hardware security measure and specifically targets digital signal processing (DSP) circuits which are part of most modern systems. The idea of using desired and undesired modes to design obfuscated DSP functions is illustrated using the fast Fourier transform (FFT) as an example. The selection of a mode is dependent on a key input to the circuit. The system is said to work in its desired mode of operation only if the correct key is applied. Other undesired modes are built into the design to confuse an adversary. The approach to obfuscating the design involves control-flow modifications which alter the computations from the desired mode. We present simulation and synthesis results on a reconfigurable, 2-parallel FFT and discuss the security of this approach. It is shown that the proposed approach results in a reconfigurable and flexible design at an area overhead of 8% and a power overhead of 10%.

Original languageEnglish (US)
Title of host publicationProceedings of the 3rd Workshop on Cryptography and Security in Computing Systems, CS2 2016
PublisherAssociation for Computing Machinery
Number of pages6
ISBN (Electronic)9781450340656
StatePublished - Jan 20 2016
Event3rd Workshop on Cryptography and Security in Computing Systems, CS2 2016 - Prague, Czech Republic
Duration: Jan 20 2016 → …

Publication series

NameACM International Conference Proceeding Series


Other3rd Workshop on Cryptography and Security in Computing Systems, CS2 2016
Country/TerritoryCzech Republic
Period1/20/16 → …


  • Control-flow modification
  • Design obfuscation
  • Fast fourier transforms (FFT)
  • Mode-based obfuscation


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