Mixed basis quantum key distribution with linear optics
This work addresses the need for more secure and practical quantum key distribution protocols, offering incremental improvements in resistance to attacks for quantum communication applications.
The authors tackled the problem of improving efficiency and loss tolerance in quantum key distribution by proposing a two-qubit protocol using a mixed basis of Bell and computational states, which can be generated from a single entangled photon pair with local operations and deterministically discriminated using linear optics, resulting in much improved resistance against certain attacks compared to the standard BB84 protocol.
Two-qubit quantum codes have been suggested to obtain better efficiency and higher loss tolerance in quantum key distribution. Here, we propose a two-qubit quantum key distribution protocol based on a mixed basis consisting of two Bell states and two states from the computational basis. All states can be generated from a single entangled photon pair resource by using local operations on only one auxiliary photon. Compared to other schemes it is also possible to deterministically discriminate all states using linear optics. Additionally, our protocol can be implemented with today's technology. When discussing the security of our protocol we find a much improved resistance against certain attacks as compared to the standard BB84 protocol.