CLOAQ: Combined Logic and Angle Obfuscation for Quantum Circuits

2026-02-27

AI Summary

This work proposes CLOAQ, a novel quantum circuit obfuscation technique designed to mitigate the risks of quantum circuit design leakage and intellectual property theft posed by untrusted quantum compilers. CLOAQ uniquely integrates logical structure obfuscation with phase angle obfuscation in a coordinated manner. Its security is rigorously evaluated by uniformly sampling input states within Hilbert space. Compared to existing approaches that rely on a single obfuscation strategy, CLOAQ substantially enhances resistance against reverse engineering and induces significantly stronger functional perturbations under incorrect decryption keys, thereby effectively improving both the confidentiality and robustness of quantum circuits.

Technology Category

• Machine Learning: Quantum Machine Learning
• Computer Vision: Adversarial Attacks & Robustness
• Constraint Satisfaction and Optimization: Satisfiability

Application Category

• Security and Privacy: Applications of cryptography
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

In the realm of quantum computing, quantum circuits serve as essential depictions of quantum algorithms, which are then compiled into executable operations for quantum computations. Quantum compilers are responsible for converting these algorithmic quantum circuits into versions compatible with specific quantum hardware, thus connecting quantum software with hardware. Nevertheless, untrusted quantum compilers present notable threats. They have the potential to result in the theft of quantum circuit designs and jeopardize sensitive intellectual property (IP). In this work, we propose CLOAQ, a quantum circuit obfuscation (QCO) approach that hides the logic and the phase angles of selected gates within the obfuscated quantum circuit. To evaluate the effectiveness of CLOAQ, we sample the input state uniformly from the Hilbert space of all qubits, which is more accurate than prior work that use all-|0>inputs. Our results show that CLOAQ benefits from the synergy between logic and phase protections. Compared with prior QCO approaches using only one perspective, the combined method is more resilient to attacks and causes greater functional disruption when the unlocking key is incorrect.

Problem

• quantum circuit obfuscation
• intellectual property protection
• untrusted quantum compilers
• quantum computing security

Innovation

• quantum circuit obfuscation
• logic-angle synergy
• phase angle protection
• quantum IP security
• Hilbert space sampling