Paper 2019/059

BeSAT: Behavioral SAT-based Attack on Cyclic Logic Encryption

Yuanqi Shen, You Li, Amin Rezaei, Shuyu Kong, David Dlott, and Hai Zhou


Cyclic logic encryption is newly proposed in the area of hardware security. It introduces feedback cycles into the circuit to defeat existing logic decryption techniques. To ensure that the circuit is acyclic under the correct key, CycSAT is developed to add the acyclic condition as a CNF formula to the SAT-based attack. However, we found that it is impossible to capture all cycles in any graph with any set of feedback signals as done in the CycSAT algorithm. In this paper, we propose a behavioral SAT-based attack called BeSAT. BeSAT observes the behavior of the encrypted circuit on top of the structural analysis, so the stateful and oscillatory keys missed by CycSAT can still be blocked. The experimental results show that BeSAT successfully overcomes the drawback of CycSAT.

Available format(s)
Publication info
Published elsewhere. Minor revision.Asian South Pacific Design Automation Conference
logic encryptionSAT-based attackcyclic circuit
Contact author(s)
haizhou @ northwestern edu
2019-01-25: received
Short URL
Creative Commons Attribution


      author = {Yuanqi Shen and You Li and Amin Rezaei and Shuyu Kong and David Dlott and Hai Zhou},
      title = {BeSAT: Behavioral SAT-based Attack on Cyclic Logic Encryption},
      howpublished = {Cryptology ePrint Archive, Paper 2019/059},
      year = {2019},
      note = {\url{}},
      url = {}
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