量子密码学长期以来依赖这样的期待：量子电脑终将威胁今日的密码，促使研究人员设计新的防护，甚至基于量子力学本身的通讯方案。这篇文章提出一个更深的问题：如果量子力学不是自然界的最终理论，这些协议还能保持安全吗？Ravishankar Ramanathan 与其他人主张把假设降到最低，并超越量子理论去寻找更基本的概念，尤其是因果性，因为量子重力等尚未解决的张力暗示，后量子框架可能会非常不同。
核心例子是量子金钥分配，它利用纠缠与纠缠的单配性来侦测窜改：如果外部者干预其中一个粒子，纠缠就会被破坏，入侵也会暴露。量子干扰是指一种假想过程，其中第三方在不违反无讯号原则的情况下，微妙地改变遥远纠缠粒子之间的关联。这个想法可追溯到 1990 年代中期 Jacob Grunhaus、Sandu Popescu 和 Daniel Rohrlich 的工作，但在 2000 年代随著装置无关量子金钥分配的发展而重新受到关注。在这个故事中，像“Jim”这样的干扰者可以把原本相反的结果转变成一致的结果，而每位参与者在局部仍只会看到任一结果各有 50% 的机率。
其影响既实际又基础：如果干扰是可能的，那么装置无关密码学所依赖的纠缠单配性就会失效，研究人员也需要更深层的原理来解释自然允许哪些关联。Roger Colbeck 和 V. Vilasini 正把干扰当作分类不同理论中因果关系的测试案例，而 Ramanathan、Paweł Horodecki、Michał Eckstein、Weilenmann 等人最近也在论文与一篇 2025 年 12 月的预印本中重新检视这个主题。文章把干扰描绘成一种探测方式，用来检验物理是否能在不违反因果性的前提下允许这类现象，以及是否能找出一条比无讯号更基本的规则。
Quantum cryptography has long relied on the expectation that quantum computers will eventually threaten today’s codes, pushing researchers to design new protections and even communication schemes based on quantum mechanics itself. The article asks a deeper question: if quantum mechanics is not the final theory of nature, could these protocols still be secure? Ravishankar Ramanathan and others argue for minimizing assumptions and looking beyond quantum theory to more basic ideas, especially causality, because unresolved tensions such as quantum gravity suggest that a post-quantum framework may be very different.
The central example is quantum key distribution, which uses entanglement and the monogamy of entanglement to detect tampering: if an outsider meddles with one particle, the entanglement is destroyed and the intrusion is exposed. Quantum jamming is a hypothetical process in which a third party subtly changes the correlation between distant entangled particles without breaking the no-signaling rule. The idea dates back to work in the mid-1990s by Jacob Grunhaus, Sandu Popescu, and Daniel Rohrlich, but it gained new life in the 2000s as device-independent quantum key distribution developed. In this story, a jammer like “Jim” can transform initially opposite outcomes into matching ones, while each participant still sees only a 50% chance of either outcome locally.
The implications are both practical and foundational: if jamming is possible, then the monogamy of entanglement on which device-independent cryptography rests would fail, and researchers would need a deeper principle to explain what kinds of correlations nature allows. Roger Colbeck and V. Vilasini are using jamming as a test case to classify cause and effect across theories, while Ramanathan, Paweł Horodecki, Michał Eckstein, Weilenmann, and others have recently revisited the topic in papers and a December 2025 preprint. The article frames jamming as a way to probe whether physics can permit such phenomena without violating causality, and whether a more fundamental rule beyond no-signaling can be identified.