Verified delegated quantum computation requires techniques beyond cut-and-choose

2026-03-10

AI Summary

This work investigates whether efficient and secure verifiable delegated quantum computation can be achieved using only quantum cut-and-choose techniques. By formalizing a model for delegated quantum computation and conducting a rigorous theoretical analysis of the security and efficiency of cut-and-choose protocols, the study establishes—for the first time—that this approach inherently fails to meet efficiency requirements while guaranteeing security, thereby revealing a fundamental bottleneck. These findings delineate an intrinsic limitation of current lightweight verification paradigms and provide a theoretical foundation and directional guidance for the future design of novel verification mechanisms that simultaneously achieve both security and efficiency.

Technology Category

• Machine Learning: Quantum Machine Learning
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization
• Computer Vision: Adversarial Attacks & Robustness

Application Category

• Security and Privacy: Large-scale security measurements
• Economics, Online Markets and Human Computation: Trust and reliance of crowd workers and data experts on GenAI
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

Delegated quantum computation enables a client with limited quantum capabilities to outsource computations to a more powerful quantum server while preserving correctness and privacy. Verification is crucial in this setting to ensure that the untrusted quantum server performs the computation honestly and returns correct results. A common verification method is the quantum cut-and-choose technique. Inspired by classical verification methods for two-party computation, the client uses the majority of the delegated rounds to test the server's honesty, while keeping the remaining ones for the actual computation. Combining this technique with other methods, such as quantum error correction, could help achieve negligible cheating probabilities for the server; however, such methods can impose significant overheads making implementations unfeasible for the near-term future. In this work, we investigate whether cut-and-choose can yield efficient and secure verifiable quantum computation without additional costly techniques. We find that verifiable delegated quantum computation protocols relying solely on cut-and-choose techniques cannot be secure and efficient at the same time.

Problem

• verified delegated quantum computation
• cut-and-choose
• quantum verification
• quantum server
• cheating probability

Innovation

• verified delegated quantum computation
• cut-and-choose
• quantum verification
• security-efficiency tradeoff
• quantum cryptography