Device-independent quantum key distribution (DI-QKD) provides the gold standard for secure key exchange. Not only it allows for information-theoretic security based on quantum mechanics, but it relaxes the need to physically model the devices, hence fundamentally ruling out many quantum hacking threats to which non-DI QKD systems are vulnerable. In practice though, DI-QKD is very challenging. It relies on the loophole-free violation of a Bell inequality, a task that requires high quality entanglement to be distributed between distant parties and close to perfect quantum measurements, which is hardly achievable with current technology. Notwithstanding, recent theoretical and experimental efforts have led to the first proof-of-principle DI-QKD implementations. In this article, we review the state-of-the-art of DI-QKD by highlighting its main theoretical and experimental achievements, discussing the recent proof-of-principle demonstrations, and emphasizing the existing challenges in the field.

中文翻译：

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与设备无关的量子密钥分发的进展

独立于设备的量子密钥分发 (DI-QKD) 为安全密钥交换提供了黄金标准。它不仅允许基于量子力学的信息论安全性，而且放宽了对设备进行物理建模的需要，因此从根本上排除了许多非 DI QKD 系统易受攻击的量子黑客威胁。但在实践中，DI-QKD 非常具有挑战性。它依赖于对贝尔不等式的无漏洞违反，这项任务需要高质量的纠缠在遥远的各方之间分布并接近完美的量子测量，这在当前技术中几乎无法实现。尽管如此，最近的理论和实验努力已经导致了第一个原理验证的 DI-QKD 实现。在本文中，