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Related papers: Device-independent lower bounds on the conditional…

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The rates of quantum cryptographic protocols are usually expressed in terms of a conditional entropy minimized over a certain set of quantum states. In particular, in the device-independent setting, the minimization is over all the quantum…

Quantum Physics · Physics 2022-10-05 Peter Brown , Hamza Fawzi , Omar Fawzi

This paper introduces a numerical framework for establishing lower bounds on the conditional von-Neumann entropy in device-independent quantum cryptography and randomness extraction scenarios. Leveraging a hierarchy of semidefinite programs…

Quantum Physics · Physics 2025-08-22 Gereon Koßmann , René Schwonnek

Variational techniques have been recently developed to find tighter bounds on the von Neumann entropy in a completely device-independent (DI) setting. This, in turn, has led to significantly improved key rates of DI protocols, in both the…

Quantum Physics · Physics 2024-08-23 Thomas A. Hahn , Ernest Y. -Z. Tan , Peter Brown

According to the entropy accumulation theorem, proving the unconditional security of a device-independent quantum key distribution protocol reduces to deriving tradeoff functions, i.e., bounds on the single-round von Neumann entropy of the…

Quantum Physics · Physics 2022-10-28 Michele Masini , Stefano Pironio , Erik Woodhead

Computing the key rate in quantum key distribution (QKD) protocols is a long standing challenge. Analytical methods are limited to a handful of protocols with highly symmetric measurement bases. Numerical methods can handle arbitrary…

Quantum Physics · Physics 2023-05-25 Mateus Araújo , Marcus Huber , Miguel Navascués , Matej Pivoluska , Armin Tavakoli

To generate genuine random numbers, random number generators based on quantum theory are essential. However, ensuring that the process used to produce randomness meets desired security standards can pose challenges for traditional quantum…

Quantum Physics · Physics 2023-11-23 Rutvij Bhavsar

The device-independent framework constitutes the most pragmatic approach to quantum protocols that does not put any trust in their implementations. It requires all claims, about e.g. security, to be made at the level of the final classical…

In this work, we develop upper bounds for key rates for device-independent quantum key distribution (DI-QKD) protocols and devices. We study the reduced cc-squashed entanglement and show that it is a convex functional. As a result, we show…

Quantum Physics · Physics 2023-01-03 Eneet Kaur , Karol Horodecki , Siddhartha Das

Device-independent quantum key distribution (DIQKD) provides the strongest form of secure key exchange, using only the input-output statistics of the devices to achieve information-theoretic security. Although the basic security principles…

We Haar uniformly generate random states of various ranks and study their performance in an entanglement-based quantum key distribution (QKD) task. In particular, we analyze the efficacy of random two-qubit states in realizing…

Quantum Physics · Physics 2023-02-14 Subhankar Bera , Shashank Gupta , A. S. Majumdar

We introduce a systematic method for constructing polytope approximations to the quantum set in a variety of device-independent quantum random number generation (DI-QRNG) protocols. Our approach relies on two general-purpose algorithms that…

Quantum Physics · Physics 2026-03-11 Hyejung H. Jee , Florian J. Curchod , Mafalda L. Almeida

Quantum Key Distribution (QKD) protocols enable two distant parties to communicate with information-theoretically proven secrecy. However, these protocols are generally vulnerable to potential mismatches between the physical modeling and…

Quantum Physics · Physics 2026-01-22 Corentin Lanore , Xavier Valcarce , Jean Etesse , Anthony Martin , Jean-Daniel Bancal

Device-independent quantum key distribution (DIQKD) is one of the most challenging tasks in quantum cryptography. The protocols and their security are based on the existence of Bell inequalities and the ability to violate them by measuring…

Quantum Physics · Physics 2025-06-09 Rotem Arnon , Felix Leditzky

The device-independent approach to quantum key distribution (QKD) aims to establish a secret key between two or more parties with untrusted devices, potentially under full control of a quantum adversary. The performance of a QKD protocol…

Quantum Physics · Physics 2018-02-07 Timo Holz , Hermann Kampermann , Dagmar Bruß

A device-independent randomness expansion protocol aims to take an initial random string and generate a longer one, where the security of the protocol does not rely on knowing the inner workings of the devices used to run it. In order to do…

Quantum Physics · Physics 2026-01-06 Rutvij Bhavsar , Sammy Ragy , Roger Colbeck

Quantum secret sharing (QSS) enables a dealer to securely distribute keys to multiple players. Device-independent (DI) QSS can resist all possible attacks from practical imperfect devices and provide QSS the highest level of security in…

Finite key analysis of quantum key distribution (QKD) is an important tool for any QKD implementation. While much work has been done on the framework of finite key analysis, the application to individual protocols often relies on the the…

Quantum Physics · Physics 2021-03-29 Ian George , Jie Lin , Norbert Lütkenhaus

One of the main challenges in device-independent quantum key distribution (DIQKD) is achieving the required Bell violation over long distances, as the channel losses result in low overall detection efficiencies. Recent works have explored…

Quantum Physics · Physics 2024-10-11 Ernest Y. -Z. Tan , Ramona Wolf

A device-independent randomness expansion protocol aims to take an initial random seed and generate a longer one without relying on details of how the devices operate for security. A large amount of work to date has focussed on a particular…

Quantum Physics · Physics 2020-06-08 Peter J. Brown , Sammy Ragy , Roger Colbeck

In the implementation of device-independent quantum key distribution we are interested in maximizing the key rate, i.e. the number of key bits that can be obtained per signal, for a fixed security parameter. In the finite size regime, we…

Quantum Physics · Physics 2019-07-25 Gláucia Murta , Suzanne B. van Dam , Jérémy Ribeiro , Ronald Hanson , Stephanie Wehner
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