Rescuing Logic Encryption in Post-SAT Era by Locking & Obfuscation
Amin Rezaeia, Yuanqi Shenb and Hai Zhouc
Northwestern University, Evanston, IL, USA
ame@aminrezaei.com
byuanqishen2020@u.northwestern.edu
chaizhou@northwestern.edu
ABSTRACT
The active participation of external entities in the manufacturing flow has produced numerous hardware security issues in which piracy and overproduction are likely to be the most ubiquitous and expensive ones. The main approach to prevent unauthorized products from functioning is logic encryption that inserts key-controlled gates to the original circuit in a way that the valid behavior of the circuit only happens when the correct key is applied. The challenge for the security designer is to ensure neither the correct key nor the original circuit can be revealed by different analyses of the encrypted circuit. However, in state-of-the-art logic encryption works, a lot of performance is sold to guarantee security against powerful logic and structural attacks. This contradicts the primary reason of logic encryption that is to protect a precious design from being pirated and overproduced. In this paper, we propose a bilateral logic encryption platform that maintains high degree of security with small circuit modification. The robustness against exact and approximate attacks is also demonstrated.
Keywords: Logic Encryption, Logic Locking, Circuit Obfuscation, SAT-based Attack, Logic Complexity, Structural Complexity, Affectability Ratio, Corruptibility Ratio.
