Blind quantum computation (BQC) allows low-resource clients to securely delegate computations to a quantum server, but server resource costs scale with the computation size, posing a bottleneck for implementations. By leveraging Pauli-based computation (PBC), we achieve BQC with a server whose size depends only on the non-Clifford gate count. Our protocol inherits fault tolerance and qubit virtualization from PBC and reveals that classical-client BQC is possible even in the absence of classical simulability. Finally, we present an entanglement-based dual protocol that performs a resource state computation with a dramatically reduced execution cost.
Blind quantum computation (BQC) allows low-resource clients to securely delegate computations to a quantum server, but server resource costs scale with the computation size, posing a bottleneck for implementations. By leveraging Pauli-based computation (PBC), we achieve BQC with a server whose size depends only on the non-Clifford gate count. Our protocol inherits fault tolerance and qubit virtualization from PBC and reveals that classical-client BQC is possible even in the absence of classical simulability. Finally, we present an entanglement-based dual protocol that performs a resource state computation with a dramatically reduced execution cost.
Abstract Blind quantum computation (BQC) allows clients with limited quantum capabilities to delegate computational tasks to remote quantum servers while keeping the privacy of their data. However, existing BQC protocols often fail to balance resource consumption and practical feasibility, which is particularly significant in the noisy intermediate-scale quantum era. In this paper, we propose a practical BQC model based on the parity quantum computing framework. It requires the server to perform operations only on adjacent qubits and eliminates the need for additional SWAP gates when two-qubit gates should be applied to non-adjacent qubits, greatly facilitating the physical implementation on real quantum devices. Furthermore, we prove that the proposed BQC model ensures the privacy of client’s information and satisfies the property of verifiability which enables clients to identify dishonest servers. Finally, a detailed example is given and simulated on the IBM’s quantum platform to demonstrate its feasibility.
Blind quantum computing (BQC) is a computational paradigm that allows a client with limited quantum capabilities to delegate quantum computations to a more powerful server while keeping both the algorithm and data hidden. However, in practice, existing BQC protocols face significant challenges when scaling to large-scale computations due to photon losses, low efficiencies, and high overheads associated with fault-tolerant operations, requiring the client to compile both logical operations and error correction primitives. We use a recently demonstrated hybrid light-matter approach [PRL 132, 150604 (2024); Science 388, 509-513 (2025)] to develop an architecture for scalable fault-tolerant blind quantum computation. By combining high-fidelity local gates on the server's matter qubits with delegated blind rotations using photons, we construct loss-tolerant delegated gates that enable efficient algorithm compilation strategies and a scalable approach for fault-tolerant blind logical algorithms. Our approach improves the error-correction threshold and increases the speed and depth of blind logical circuits. Finally, we outline how this architecture can be implemented on state-of-the-art quantum hardware, including neutral atom arrays and solid-state spin defects. These new capabilities open up new opportunities for deep circuit blind quantum computing.
Blind quantum computing (BQC) enables a client with limited quantum capability to delegate her quantum computation to a remote quantum server and still keeps the client's input, output, and the algorithm private. One important property of BQC is verifiability, which means the client can verify the correctness of the computation or unknown quantum inputs. Recently, Morimae proposed a verifiable blind quantum computing protocol where the client can verify both the correctness of computing and the quantum input. However, the client needs much quantum memory and takes a lot of qubits to get the true result. We reduce the size of quantum memory and the number of qubits used in Morimae's protocol. Besides, we extend the resource state in Morimae's protocol from graph state to hypergraph state. For certain hypergraph states as resources states, such as Union Jack State, the client only needs Pauli measurements in the computation stage but he needs non-Clifford basis measurements if graph states are considered as resources states.
The scarcity of quantum resources is a significant theme in quantum cryptography and computation. Within quantum cryptography, secure delegated quantum computation (SDQC) allows low-resource users to access quantum computation with privacy. From the study of models of quantum computation, Pauli-based computation (PBC) has emerged as a resource-efficient alternative to conventional models. In this thesis, we merge these two strands of work, presenting the first protocol for SDQC in the PBC model. Our protocol allows a client with minimal quantum resources to execute a PBC on a secret classical input of their choice by interacting with a quantum server. We prove that the protocol gives the client perfect, information-theoretic security. Our protocol inherits the resource efficiencies of PBC, significantly reducing the size of the quantum register required by the server, implying that SDQC could be available sooner than anticipated in a world of scarce quantum resources.
Blind quantum computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client's input, output, and computation remain private. A desirable property for any BQC protocol is verification, whereby the client can verify with high probability whether the server has followed the instructions of the protocol or if there has been some deviation resulting in a corrupted output state. A verifiable BQC protocol can be viewed as an interactive proof system leading to consequences for complexity theory. We previously proposed [A. Broadbent, J. Fitzsimons, and E. Kashefi, in Proceedings of the 50th Annual Symposium on Foundations of Computer Science, Atlanta, 2009 (IEEE, Piscataway, 2009), p. 517] a universal and unconditionally secure BQC scheme where the client only needs to be able to prepare single qubits in separable states randomly chosen from a finite set and send them to the server, who has the balance of the required quantum computational resources. In this paper we extend that protocol with additional functionality allowing blind computational basis measurements, which we use to construct another verifiable BQC protocol based on a different class of resource states. We rigorously prove that the probability of failing to detect an incorrect output is exponentially small in a security parameter, while resource overhead remains polynomial in this parameter. This resource state allows entangling gates to be performed between arbitrary pairs of logical qubits with only constant overhead. This is a significant improvement on the original scheme, which required that all computations to be performed must first be put into a nearest-neighbor form, incurring linear overhead in the number of qubits. Such an improvement has important consequences for efficiency and fault-tolerance thresholds.
Blind quantum computation (BQC) is a type of quantum computation model. For a client (Alice) who does not have enough sophisticated technology and knowledge to perform universal quantum computation, BQC allows her to resort to a remote quantum computation server (Bob) to delegate universal quantum computation. During the computation, Bob cannot know Alice's inputs, algorithm, and outputs. A single-server BQC protocol requires Alice to prepare and distribute single-photon states to Bob. Unfortunately, the distributed single photons will suffer from noise. The noise not only leads to the decoherence of the single-photon state, but also leads to photon loss. In this protocol, we describe an antinoise single-server BQC protocol. This protocol has three advantages. First, Alice does not require any auxiliary resources, which reduces the client's economic cost. Second, this protocol not only can protect the state from the collective noise, but also can distill the single photon from photon loss. Third, the noise processer in Bob is based on the linear optics so that it is feasible in experiment. This protocol may show that it is possible to perform a single-server BQC protocol in a noise channel.