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arXiv · 2402.18648

Linear gate bounds against natural functions for position-verification

Vahid Asadi·Richard Cleve·Eric Culf·Alex May
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Abstract

A quantum position-verification scheme attempts to verify the spatial location of a prover. The prover is issued a challenge with quantum and classical inputs and must respond with appropriate timings. We consider two well-studied position-verification schemes known as $f$-routing and $f$-BB84. Both schemes require an honest prover to locally compute a classical function $f$ of inputs of length $n$, and manipulate $O(1)$ size quantum systems. We prove the number of quantum gates plus single qubit measurements needed to implement a function $f$ is lower bounded linearly by the communication complexity of $f$ in the simultaneous message passing model with shared entanglement. Taking $f(x,y)=\sum_i x_i y_i$ to be the inner product function, we obtain a $\Omega(n)$ lower bound on quantum gates plus single qubit measurements. The scheme is feasible for a prover with linear classical resources and $O(1)$ quantum resources, and secure against sub-linear quantum resources.

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Vahid Asadi, Richard Cleve, Eric Culf, Alex May. 2024-02-28. Linear gate bounds against natural functions for position-verification. https://doi.org/10.22331/q-2025-01-21-1604

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