论文标题
经典Quantum窃听通道中的非促进性
Non-additivity in classical-quantum wiretap channels
论文作者
论文摘要
由于Csiszar和Koerner，经典窃听通道的私人容量在私人信息方面具有单个字母的表征。但是，对于量子窃听通道，众所周知，私人信息的正则化对于达到容量是必要的。在这里，我们研究了混合经典的Quantum窃听通道，以解决在量子Shannon理论中需要在多大程度上见证量子效应的程度。对于具有量子输入但经典输出的窃听通道，我们证明了私人信息的能力表征保持单字母。因此，在这种情况下，纠缠的输入状态没有渐近优势。对于具有经典输入的窃听通道，我们通过明确的示例显示，当两个接收器中的任何一个都变成量子时（另一个接收器保持经典）时，私人信息已经变得不添加。这给出了非纠缠引起的非添加示例，并说明了量子对手与窃听模型中的经典对手有严格的不同。
Due to Csiszar and Koerner, the private capacity of classical wiretap channels has a single-letter characterization in terms of the private information. For quantum wiretap channels, however, it is known that regularization of the private information is necessary to reach the capacity. Here, we study hybrid classical-quantum wiretap channels in order to resolve to what extent quantum effects are needed to witness non-additivity phenomena in quantum Shannon theory. For wiretap channels with quantum inputs but classical outputs, we prove that the characterization of the capacity in terms of the private information stays single-letter. Hence, entangled input states are of no asymptotic advantage in this setting. For wiretap channels with classical inputs, we show by means of explicit examples that the private information already becomes non-additive when either one of the two receivers becomes quantum (with the other receiver staying classical). This gives non-additivity examples that are not caused by entanglement and illustrates that quantum adversaries are strictly different from classical adversaries in the wiretap model.
