Quantum key distribution based on hyperentanglement swapping
基于超纠缠交换的量子密钥分发

We present a quantum key distribution scheme based on hyperentanglement swapping, which can simultaneously generate deterministic and random keys without the loss of security. The scheme only requires two\|photon states entangled both in spatial (path) and polarization modes, and such a photon pair can create 4 bit of secure keys (2 bit of random keys and 2 bit of deterministic keys). Our protocol can be implemented with linear optics under current technology.