论文标题
多伙性设备无关加密的熵边界
Entropy bounds for multiparty device-independent cryptography
论文作者
论文摘要
基于分布式纠缠的多方量子密码学将在即将到来的量子网络中找到其自然应用。诸如DI会议关键协议之类的许多多部分设备（DI）协议的安全性依赖于违反了多方钟的不等式的范围，以窃听者的信息为条件。我们考虑三方测试Mermin-Ardehali-Belinskii-Klyshko（MABK）不平等，并通过界定单个方结果的条件熵和两个党派的共同条件熵来证明其结果的隐私。从前者的界限中，我们表明，真正的多部分纠缠对于证明当事方结果的隐私是必要的，而后者显着改善了以前的结果。我们获得了熵的界限，这要归功于两个独立关注的一般结果。第一个大大简化了$ n $ - 明确钟场景的量子设置。第二个为违反MABK不平等的违反$ n $ qubit状态的上限作为国家参数的函数。
Multiparty quantum cryptography based on distributed entanglement will find its natural application in the upcoming quantum networks. The security of many multipartite device-independent (DI) protocols, such as DI conference key agreement, relies on bounding the von Neumann entropy of the parties' outcomes conditioned on the eavesdropper's information, given the violation of a multipartite Bell inequality. We consider three parties testing the Mermin-Ardehali-Belinskii-Klyshko (MABK) inequality and certify the privacy of their outcomes by bounding the conditional entropy of a single party's outcome and the joint conditional entropy of two parties' outcomes. From the former bound, we show that genuine multipartite entanglement is necessary to certify the privacy of a party's outcome, while the latter significantly improve previous results. We obtain the entropy bounds thanks to two general results of independent interest. The first one drastically simplifies the quantum setup of an $N$-partite Bell scenario. The second one provides an upper bound on the violation of the MABK inequality by an arbitrary $N$-qubit state, as a function of the state's parameters.
