Logic Encryption: This Time for Real

TL;DR

This paper introduces a practical logic encryption scheme for circuit IP protection that encrypts circuit logic itself, outperforming prior methods against various attacks with lower overheads.

Contribution

It presents a novel, end-to-end logic encryption approach combining cryptography, randomization, and design techniques, improving security and efficiency over existing schemes.

Findings

Outperforms prior art against oracle-less attacks

Lower design overheads compared to existing methods

Provides an open-source implementation

Abstract

Modern circuits face various threats like reverse engineering, theft of intellectual property (IP), side-channel attacks, etc. Here, we present a novel approach for IP protection based on logic encryption (LE). Unlike established schemes for logic locking, our work obfuscates the circuit's structure and functionality by encoding and encrypting the logic itself. We devise an end-to-end method for practical LE implementation based on standard cryptographic algorithms, key-bit randomization, simple circuit design techniques, and system-level synthesis operations, all in a correct-by-construction manner. Our extensive analysis demonstrates the remarkable efficacy of our scheme, outperforming prior art against a range of oracle-less attacks covering crucial threat vectors, all with lower design overheads. We provide a full open-source release.