Yao Ma

Proofs of quantumness (PoQ) allows a classical verifier to certify that a remote prover possesses genuine quantum computational power. While existing PoQ protocols primarily address security against malicious provers, recent work by Phan et al. introduced zero-knowledge proofs of quantumness (ZKPoQ) to additionally protect honest provers from malicious verifiers seeking to extract information beyond the mere fact of quantum capability. In this work, we advance the ZKPoQ framework with two concrete contributions aimed at practical deployment. First, we instantiate two interactive ZKPoQ protocols---based on factoring and on learning with errors (LWE), respectively---each incorporating an extractable zero-knowledge gadget that the verifier must provide on its witness before the PoQ protocol proceeds. Notably, our constructions eliminate the dependency on a common reference string (CRS) required in prior work, thereby reducing architectural assumptions and simplifying real-world adoption. Second, we apply the Fiat--Shamir heuristic to transform both interactive protocols into non-interactive variants, improving communication efficiency. We formally prove that our schemes satisfy quantum completeness, classical soundness, and computational zero-knowledge under the ZKPoQ framework. Finally, we propose concrete parameter settings for practical deployment, provide a detailed analysis of communication costs across both interactive and non-interactive variants, and present a comparative summary of their efficiency trade-offs.

We introduce a secure hardware device named a QEnclave that can secure the remote execution of quantum operations while only using classical controls. This device extends to quantum computing the classical concept of a secure enclave which isolates a computation from its environment to provide privacy and tamper-resistance. Remarkably, our QEnclave only performs single-qubit rotations, but can nevertheless be used to secure an arbitrary quantum computation even if the qubit source is controlled by an adversary. More precisely, attaching a QEnclave to a quantum computer, a remote client controlling the QEnclave can securely delegate its computation to the server solely using classical communication. We investigate the security of our QEnclave by modeling it as an ideal functionality named Remote State Rotation. We show that this resource allows blind delegated quantum computing with perfect security. Our proof relies on standard tools from delegated quantum computing. Working in the Abstract Cryptography framework, we show a construction of remote state preparation from remote state rotation preserving the security. An immediate consequence is the weakening of the requirements for blind delegated computation. While previous delegated protocols were relying on a client that can either generate or measure quantum states, we show that this same functionality can be achieved with a client that only transforms quantum states without generating or measuring them. Combined with known impossibility results for implementing remote state preparation with classical communication, our construction suggests a new way for blind secure delegated computation. Computational assumptions that circumvent this impossibility induce large overheads that prevent their practical use. But our approach does not increase the complexity of the problem, and relies on hardware assumptions that are already used in practice for classical computations. It hence provides a better way of implementing blind remote delegation on real quantum computing systems.