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After quantum computers come out, governments and rich companies will have the abilities to buy these useful quantum computers, meanwhile they are familiar with these technologies proficiently. If a client wants to perform quantum computing but she does not have quantum computers with relevant quantum technologies. She can seek help from the server and pay his salary, but she does not want to leak anything to the server. Blind quantum computing (BQC) give a good method for the client to realized her quantum computing. In this article, we propose a new BQC protocol of quantum fourier transform (QFT) performed on multi-qubit states with a trusted, a client and a server, where the trusted center can generate resource states, the client can delegate her quantum computing to a server who can perform universal quantum computing without knowing anything about the clients inputs, algorithms and outputs. We first give the BQC protocols of three-qubit QFT with the equivalently quantum circuits, Greenberg-Horne-Zeilinger(GHZ) entangled states and W entangled states as examples. Further, we extend them to multi-qubit QFT on multi-qubit with the equivalently quantum circuits. At last, we give the analyses and proofs of the blindness and correctness.
It is called blind quantum computation(BQC) that a client who has limited quantum technologies can delegate her quantum computing to a server who has fully-advanced quantum computers. But the privacy of the clients quantum inputs, algorithms and outputs is still a challenge. To realize a secure BQC, we mainly study how to hide quantum fourier transform (QFT) performed on Bell states. In this paper, three cases are considered as follows. For the first case, we design primary BQC protocols of QFT performed on qubits 12 of belonging to ${|phi^pmrangle_{12},$ $|psi^pmrangle_{12}}$ with relevant circuits. To strengthen security, we construct enhanced BQC protocols of QFT performed on qubits 13 of any two Bell states $|xirangle_{12}otimes|thetarangle_{34}$ with relevant quantum circuits. Featured the property of stronger security, we give generalized BQC protocols of QFT performed on qubits 13 and 24 of any two Bell states with relevant quantum circuits respectively. At last, we analyze and prove the blindness and correctness.
Blind quantum computation (BQC) is a new type of quantum computation model. BQC allows a client (Alice) who does not have enough sophisticated technology and knowledge to perform universal quantum computation and resorts a remote quantum computation server (Bob) to delegate universal quantum computation. During the computation, Bob cannot know Alices inputs, algorithm and outputs. In single-server BQC protocol, it requires Alice to prepare and distribute single-photon states to Bob. Unfortunately, the distributed single photons will suffer from noise, which not only makes the single-photon state decoherence, but also makes it loss. In this protocol, we describe an anti-noise BQC protocol, which combined the ideas of faithful distribution of single-photon state in collective noise, the feasible quantum nondemolition measurement and Broadbent-Fitzsimons-Kashefi (BFK) protocol. This protocol has several advantages. First, Alice does not require any auxiliary resources, which reduces the clients 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 setup in Bob is based on the linear optics, and it is also feasible in experiment. This anti-noise BQC may show that it is possible to perform the BQC protocol in a noisy environment.
Blind quantum computation allows a client without enough quantum technologies to delegate her quantum computation to a remote quantum server, while keeping her input, output and algorithm secure. In this paper, we propose a universal single-server and almost-classical-client blind quantum computation protocol. In this protocol, the client interfaces with only one server and the only ability of the client required is to get particles from the trusted center and forward them to the server. We present an analysis of this protocol and modify it to a universal single-server and fully-classical-client blind quantum computation protocol by improving the ability of the trusted center. Based on our protocols and recent works, a new Cloud + Certificate Authority (CA) style is proposed for the blind quantum computation.
Blind quantum computation (BQC) allows that a client who has limited quantum abilities can delegate quantum computation to a server who has advanced quantum technologies but learns nothing about the clients private information. For example, measurement-based model can guarantee privacy of clients inputs, quantum algorithms and outputs. However, it still remains a challenge to directly encrypt quantum algorithms in circuits model. To solve the problem, we propose GTUBQC, the first gate teleportation-based universal BQC protocol. Specifically, in this paper we consider a scenario where there are a trusted center responsible for preparing initial states, a client with the ability to perform X, Z, and two non-communicating servers conducting UBQC (universal BQC) and Bell measurements. GTUBQC ensures that all quantum outputs are at the clients side and the client only needs to detect whether servers honestly return correct measurement outcomes or not. In particular, GTUBQC can hide the universal quantum gates by encrypting the rotation angles, because arbitrary unitary operation can be decomposed into a combination of arbitrary rotation operators. Also, GTUBQC protocol can facilitate realizing UBQC in circuits, since GTUBQC uses one-time-pad to guarantee blindness. We prove the blindness and correctness of GTUBQC, and apply our approach to other types of computational tasks, such as quantum Fourier transform.
In blind quantum computation (BQC), a client delegates her quantum computation to a server with universal quantum computers who learns nothing about the clients private information. In measurement-based BQC model, entangled states are generally used to realize quantum computing. However, to generate a large-scale entangled state in experiment becomes a challenge issue. In circuit-based BQC model, single-qubit gates can be realized precisely, but entangled gates are probabilistically successful. This remains a challenge to realize entangled gates with a deterministic method in some systems. To solve above two problems, we propose the first hybrid universal BQC protocol based on measurements and circuits, where the client prepares single-qubit states and the server performs universal quantum computing. We analyze and prove the correctness, blindness and verifiability of the proposed protocol.