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arXiv · 2507.07365

Analytic R\'enyi Entropy Bounds for Device-Independent Cryptography

Thomas A. Hahn·Aby Philip·Ernest Y. -Z. Tan·Peter Brown
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Abstract

Device-independent (DI) cryptography represents the highest level of security, enabling cryptographic primitives to be executed safely on uncharacterized devices. Moreover, with successful proof-of-concept demonstrations in randomness expansion, randomness amplification, and quantum key distribution, the field is steadily advancing toward commercial viability. Critical to this continued progression is the development of tighter finite-size security proofs. In this work, we provide a simple method to obtain tighter finite-size security proofs for protocols based on the CHSH game, which is the nonlocality test used in all of the proof-of-concept experiments. We achieve this by analytically solving key-rate optimization problems based on R\'enyi entropies, providing a simple method to obtain tighter finite-size key rates.

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Thomas A. Hahn, Aby Philip, Ernest Y. -Z. Tan, Peter Brown. 2025-07-10. Analytic R\'enyi Entropy Bounds for Device-Independent Cryptography. https://arxiv.org/abs/2507.07365

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