Paper 2017/626

CycSAT: SAT-Based Attack on Cyclic Logic Encryptions

Hai Zhou, Ruifeng Jiang, and Shuyu Kong


Cyclic logic encryption is a newly proposed circuit obfuscation technique in hardware security. It was claimed to be SAT-unresolvable because feedback cycles were intentionally inserted under keys into the encryption. We show in the paper that even though feedback cycles introduce extra difficulty for an attacker, they can still be overcome with SAT- based techniques. Specifically, we propose CycSAT Algorithms based on SAT with different acyclic conditions that can efficiently decrypt cyclic encryptions. Experimental results have shown that our CycSAT is efficient and effective to decrypt cyclic encryptions, and we need to develop new encryptions with better security properties.

Note: Minor corrections: Not For Tutorial!

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Publication info
Published elsewhere. Major revision. International Conference on Computer-Aided Design
hardware securitylogic encryptionSATcyclic circuit
Contact author(s)
haizhou @ northwestern edu
2021-04-02: revised
2017-06-27: received
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Creative Commons Attribution


      author = {Hai Zhou and Ruifeng Jiang and Shuyu Kong},
      title = {{CycSAT}: {SAT}-Based Attack on Cyclic Logic Encryptions},
      howpublished = {Cryptology ePrint Archive, Paper 2017/626},
      year = {2017},
      note = {\url{}},
      url = {}
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