aiqbench analysis
This research establishes a fundamental barrier for quantum indistinguishability obfuscation (qIO), proving it cannot rely on standard falsifiable cryptographic assumptions under specific black-box reduction constraints. By separating qIO from these common foundations, the study clarifies the theoretical limits of constructing secure witness encryption and other advanced primitives using current cryptographic paradigms. The findings highlight that achieving qIO likely requires either non-falsifiable assumptions or a departure from the restricted reduction classes analyzed here.
Separating Quantum Indistinguishability Obfuscation from Falsifiable Assumptions
arXiv:2608.25195v1 Announce Type: new Abstract: Quantum indistinguishability obfuscation (qIO) aims to make a quantum circuit unintelligible while preserving its functionality. It serves as a foundational primitive for advanced applications, such as witness encryption (WE) for QMA, non-interactive zero-knowledge arguments for QMA, and attribute-based encryption for BQP. Despite its importance, constructing qIO from standard assumptions remains a major open problem. In this work, we prove that the security of WE for QMA cannot be based on any falsifiable cryptographic assumption via a restricted class of quantum black-box reductions. Because qIO for null quantum circuits implies WE for QMA, this also separates null-qIO from falsifiable assumptions. Since almost all standard cryptographic assumptions are falsifiable, our result presents a barrier to basing qIO on standard cryptographic assumptions. The reductions we rule out are restricted: the reduction must query the adversary classically, non-adaptively, at the same security parameter, and only on honestly generated ciphertexts. Moreover, our impossibility applies only to WE with classical ciphertexts, and therefore does not rule out qIO with obfuscators whose output is a quantum state. Ruling out more general reductions, as well as more general forms of WE and qIO, remains open. Our impossibility relies on the existence of a QMA-QCIP[2] gap problem, an average-case assumption postulating a QMA language that cannot be verified with two messages of classical communication.
Abstract:Quantum indistinguishability obfuscation (qIO) aims to make a quantum circuit unintelligible while preserving its functionality. It serves as a foundational primitive for advanced applications, such as witness encryption (WE) for QMA, non-interactive zero-knowledge arguments for QMA, and attribute-based encryption for BQP. Despite its importance, constructing qIO from standard assumptions remains a major open problem. In this work, we prove that the security of WE for QMA cannot be based on any falsifiable cryptographic assumption via a restricted class of quantum black-box reductions. Because qIO for null quantum circuits implies WE for QMA, this also separates null-qIO from falsifiable assumptions. Since almost all standard cryptographic assumptions are falsifiable, our result presents a barrier to basing qIO on standard cryptographic assumptions. The reductions we rule out are restricted: the reduction must query the adversary classically, non-adaptively, at the same security parameter, and only on honestly generated ciphertexts. Moreover, our impossibility applies only to WE with classical ciphertexts, and therefore does not rule out qIO with obfuscators whose output is a quantum state. Ruling out more general reductions, as well as more general forms of WE and qIO, remains open. Our impossibility relies on the existence of a QMA-QCIP[2] gap problem, an average-case assumption postulating a QMA language that cannot be verified with two messages of classical communication.
arXiv:2608.25195 [quant-ph]
(or arXiv:2608.25195v1 [quant-ph] for this version)
https://doi.org/10.48550/arXiv.2608.25195 Focus to learn more arXiv-issued DOI via DataCite (pending registration)
arXivLabs is a framework that allows collaborators to develop and share new arXiv features directly on our website.
Both individuals and organizations that work with arXivLabs have embraced and accepted our values of openness, community, excellence, and user data privacy. arXiv is committed to these values and only works with partners that adhere to them.
Have an idea for a project that will add value for arXiv's community? Learn more about arXivLabs.
Full text under the publisher's open licence · 306 words
Related coverage
Researchers Secure Copy-Protection Using Correlated Challenges
Quantum Zeitgeist · Sep 17, 2026
Lattice-Based Cryptography Explained
Quantum Zeitgeist · Aug 15, 2026
Verifiable Quantum Advantage and Computation via Quantum Circuit Obfuscation
arXiv · Oct 1, 2026
Game On: Quantinuum Demonstrates Exponential Edge Over Classical Strategies
The Quantum Insider · Sep 8, 2026