Quantum Indistinguishable Obfuscation via Quantum Circuit Equivalence

TL;DR

This paper introduces a new quantum indistinguishable obfuscation scheme based on quantum circuit equivalence, enabling secure and confidential quantum implementations for general circuits, with implications for intellectual property and delegated quantum computing.

Contribution

It proposes a novel QiO scheme using quantum subpath sum equivalence, addressing security loss and extending obfuscation to general quantum circuits.

Findings

Feasibility demonstrated for general quantum circuit obfuscation

Introduces quantum subpath sum equivalence concept

Ensures indistinguishability of different quantum implementations

Abstract

Quantum computing solutions are increasingly deployed in commercial environments through delegated computing, especially one of the most critical issues is to guarantee the confidentiality and proprietary of quantum implementations. Since the proposal of general-purpose indistinguishability obfuscation (iO) and functional encryption schemes, iO has emerged as a seemingly versatile cryptography primitive. Existing research on quantum indistinguishable obfuscation (QiO) primarily focuses on task-oriented, lacking solutions to general quantum computing. In this paper, we propose a scheme for constructing QiO via the equivalence of quantum circuits. It introduces the concept of quantum subpath sum equivalence, demonstrating that indistinguishability between two quantum circuits can be achieved by incremental changes in quantum subpaths. The restriction of security loss is solved by reducing the distinguisher to polynomial probability test. The scheme obfuscates the quantum implementation of classical functions in a path-sum specification, ensuring the indistinguishability between different quantum implementations. The results demonstrate the feasibility of indistinguishability obfuscation for general circuits and provide novel insights on intellectual property protection and secure delegated quantum computing.