Quantum cryptography and symmetry of quantum states

针对边信息的随机性提取是从给定源中提取密钥的艺术，该密钥几乎一致地依赖于边信息。该工作提供了针对量子边信息的随机性提取，其可提取的密钥长度由条件碰撞熵的量子泛化给出，而不是基于关于量子态的最大化的常规平滑。此外，证明了当两个算符在其定义中互换时，量子条件碰撞熵的计算变得非常容易。

Randomness extraction against side information is the art of distilling from a given source a key which is almost uniform conditioned on side information. This work provided randomness extraction against quantum side information whose extractable key length is given by a quantum generalization of the conditional collision entropy defined without the conventional smoothing based on the maximization with respect to quantum states. Moreover, it was demonstrated that the evaluation of the quantum conditional collision entropy becomes drastically easy when the two operators in its definition commute.