CIPHR: Cryptography Inspired IP Protection through Fine-Grain Hardware Redaction

2026-04-03

AI Summary

This work addresses the vulnerability of hardware intellectual property (IP) in globalized integrated circuit supply chains, where untrusted third parties can compromise confidentiality and integrity through structural reverse engineering—often exploiting residual design features left by existing protection techniques. To counter this, the paper introduces CIPHR, a fine-grained hardware obfuscation method inspired by cryptographic indistinguishability. CIPHR pioneers the application of this principle to hardware security by employing heuristic-driven structural randomization to thoroughly eliminate design artifacts exploitable via known-plaintext attacks. Experimental evaluation on multiple open-source benchmark circuits demonstrates that CIPHR significantly outperforms state-of-the-art approaches in robustness, scalability, and resistance to structural attacks, achieving strong indistinguishability against such threats.

Abstract

Hardware intellectual property (IP) in the globalized integrated circuit (IC) supply chain is exposed to a wide range of confidentiality and integrity attacks by untrusted third-party entities. Existing IP-level countermeasures, such as logic locking, hardware obfuscation, camouflaging, and redaction, have aimed at addressing these them. In particular, hardware redaction has emerged as a robust approach for IP protection against confidentiality attacks, including reverse engineering. We note that existing IP protection approaches, including the ones based on hardware redaction, tend to leave behind structural artifacts that can be exploited by adversaries to bypass protections or predict unlocking keys, using the knowledge of known designs, akin to a known-plaintext attack (KPA) in cryptography. In this work, we present CIPHR, a robust fine-grain hardware redaction methodology inspired by the cryptographic property of indistinguishability. The proposed approach utilizes novel heuristic-driven randomization to introduce significant structural transformations into the redacted designs. We employ structural analysis metrics to evaluate the security achieved by CIPHR compared to various state-of-the-art IP protection techniques. Multiple open-source benchmark designs are used to demonstrate that fine-grain redaction in CIPHR is robust, scalable, and indistinguishable against structural attacks.

Problem

• hardware intellectual property
• confidentiality attacks
• structural artifacts
• known-plaintext attack
• hardware redaction

Innovation

• hardware redaction
• indistinguishability
• fine-grain randomization
• structural obfuscation
• IP protection