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Logic encryption, a method to lock a circuit from unauthorized use unless the correct key is provided, is the most important technique in hardware IP protection. However, with the discovery of the SAT attack, all traditional logic encryption algorithms are broken. New algorithms after the SAT attack are all vulnerable to structural analysis unless a provable obfuscation is applied to the locked circuit. But there is no provable logic obfuscation available, in spite of some vague resorting to logic resynthesis. In this paper, we formulate and discuss a trilemma in logic encryption among locking robustness, structural security, and encryption efficiency, showing that pre-SAT approaches achieve only structural security and encryption efficiency, and post-SAT approaches achieve only locking robustness and encryption efficiency. There is also a dilemma between query complexity and error number in locking. We first develop a theory and solution to the dilemma in locking between query complexity and error number. Then, we provide a provable obfuscation solution to the dilemma between structural security and locking robustness. We finally present and discuss some results towards the resolution of the trilemma in logic encryption.
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Global Attack and Remedy on IC-Specific Logic Encryption
In recent years, semiconductor industry has out-sourced the manufacturing to low-cost but not necessarily trusted foundries. This fabless business model encounters new security challenges, including piracy and overproduction. A well-studied solution to prevent unauthorized products from functioning is logic encryption, where a chip is encrypted using a key only known to the designer. However, the majority of the logic encryption solutions are vulnerable due to key uniformity and probing attacks. In this paper, we first present GSAT, a Global attack on existing IC-specific logic encryption schemes using the SAT model, that effectively deciphers the hidden global key pluggable to all the encrypted ICs. Next, we propose a highly secure and low-cost remedy called SPLEnD: Strong PUF -based Logic Encryption Design. Traditional I C-specific encryption schemes are vulnerable to GSAT attack, while SPLEnD not only effectively resists GSAT, but also balances security and efficiency.
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- PAR ID:
- 10356602
- Date Published:
- Journal Name:
- 2022 IEEE International Symposium on Hardware Oriented Security and Trust (HOST)
- Page Range / eLocation ID:
- 145 to 148
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/HOST54066.2022.9840128
