The monogamy of nonlocality is one the most intriguing and cryptographically significant predictions of quantum theory. The physical principle of information causality offers a promising means to understand and restrict the extent of nonlocality without invoking the abstract mathematical formalism of quantum theory. In this article, we demonstrate that the original bipartite formulation of information causality cannot imply non-trivial monogamy relations, thereby refuting the previous claims. Nevertheless, we show that the recently proposed multipartite formulation of information causality implies stronger-than-no-signaling monogamy relations. We use these monogamy relations to enhance the security of device-independent quantum key distribution against a no-signaling eavesdropper constrained by information causality.

翻译：非定域性的一夫一妻制是量子理论中最引人入胜且具有密码学重要意义的一个预言。信息因果性这一物理原理为理解和限制非定域性的程度提供了一种有前景的途径，而无需借助量子理论的抽象数学形式体系。在本文中，我们证明了原始的双体信息因果性表述无法导出非平凡的一夫一妻关系，从而否定了先前的断言。然而，我们证明了最近提出的多体信息因果性表述可以导出强于无信号限制的一夫一妻关系。我们利用这些一夫一妻关系来增强设备无关量子密钥分发的安全性，以抵御受信息因果性约束的无信号窃听者。