Finite-Key Analysis of Quantum Key Distribution with Characterized Devices Using Entropy Accumulation
Abstract
The Entropy Accumulation Theorem (EAT) was introduced to significantly improve the finite-size rates for device-independent quantum information processing tasks such as device-independent quantum key distribution (QKD). A natural question would be whether it also improves the rates for device-dependent QKD. In this work, we provide an affirmative answer to this question. We present new tools for applying the EAT in the device-dependent setting. We present sufficient conditions for the Markov chain conditions to hold as well as general algorithms for constructing the needed min-tradeoff function. Utilizing Dupuis' recent privacy amplification without smoothing result, we improve the key rate by optimizing the sandwiched R\'{e}nyi entropy directly rather than considering the traditional smooth min-entropy. We exemplify these new tools by considering several examples including the BB84 protocol with the qubit-based version and with a realistic parametric downconversion source, the six-state four-state protocol and a high-dimensional analog of the BB84 protocol.
Cite
@article{arxiv.2203.06554,
title = {Finite-Key Analysis of Quantum Key Distribution with Characterized Devices Using Entropy Accumulation},
author = {Ian George and Jie Lin and Thomas van Himbeeck and Kun Fang and Norbert Lütkenhaus},
journal= {arXiv preprint arXiv:2203.06554},
year = {2025}
}
Comments
47 + 28 pages, 8 figures; version accepted to Quantum