Measurement-Device-Independent Semi-Quantum Secure Direct Communication

Considering the high cost and high quantum resource consumption involved in measurement-device-independent quantum secure direct communication, this paper designs a measurement-device-independent quantum secure direct communication protocol based on a semi-quantum environment. This protocol appropriately reduces communication cost and quantum resource consumption by imposing certain restrictions on the quantum capabilities of one of the communication parties. Meanwhile, the protocol also ensures the high security of communication and increases secrecy channel capacity. Furthermore, given that 1-qubit in 2-dimensional system can encode a maximum of only 1-classical bit of information, the paper extends the proposed protocol to d-dimensional system. This extension further improves communication efficiency and secrecy channel capacity, laying the foundation for future research on the diversity and efficiency of information transmission.