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arXiv · 1505.04248

Blind quantum computation over a collective-noise channel

Yuki Takeuchi·Keisuke Fujii·Rikizo Ikuta·Takashi Yamamoto·Nobuyuki Imoto
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Abstract

Blind quantum computation (BQC) allows a client (Alice), who only possesses relatively poor quantum devices, to delegate universal quantum computation to a server (Bob) in such a way that Bob cannot know Alice's inputs, algorithm, and outputs. The quantum channel between Alice and Bob is noisy, and the loss over the long-distance quantum communication should also be taken into account. Here we propose to use decoherence-free subspace (DFS) to overcome the collective noise in the quantum channel for BQC, which we call DFS-BQC. We propose three variations of DFS-BQC protocols. One of them, a coherent-light-assisted DFS-BQC protocol, allows Alice to faithfully send the signal photons with a probability proportional to a transmission rate of the quantum channel. In all cases, we combine the ideas based on DFS and the Broadbent-Fitzsimons-Kashefi protocol, which is one of the BQC protocols, without degrading unconditional security. The proposed DFS-based schemes are generic and hence can be applied to other BQC protocols where Alice sends quantum states to Bob.

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Yuki Takeuchi, Keisuke Fujii, Rikizo Ikuta, Takashi Yamamoto, Nobuyuki Imoto. 2015-05-16. Blind quantum computation over a collective-noise channel. https://doi.org/10.1103/physreva.93.052307

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