Realization of Quantum Secure Direct Communication with Continuous Variable

Abstract

With the progress of theoretical and applied technologies, the communication system based on the classical encryption is seriously threatened by quantum computing and distributed computing. A communication method that directly loads confidential information on the quantum state, quantum secure direct communication (QSDC), came into being for resisting security threats. Here, we report the first continuous-variable QSDC (CV-QSDC) experimental demonstration for verifying the feasibility and effectiveness of the CV-QSDC protocol based on Gaussian mapping and propose a parameter estimation for signal classification under the actual channels. In our experiment, we provided 4 × 10 2 blocks, where each block contains 10 5 data for direct information transmission. For the transmission distance of 5 km in our experiment, the excess noise is 0.0035 SNU, where SNU represents the unit of shot-noise units. The 4.08 × 10 5 bit per second experimental results firmly demonstrated the feasibility of CV-QSDC under the fiber channel. The proposed grading judgment method based on parameter estimation provides a practical and available message processing scheme for CV-QSDC in a practical fiber channel and lays the groundwork for the grading reconciliation.

The Evolution of Quantum Secure Direct Communication: On the Road to the Qinternet

“…Concurrently, continuous variable QSDC is also transitioning from theory to experiments. This includes quantum-secured direct communication relying on squeezed states [336] and continuous variable entanglement [84], [492], [493]. The underlying theoretical protocols [85], [307], [334] employed for these experiments exhibit two-way transmission of quantum states, which is similar to the DL04 protocol [64] and to the two-step protocol [63].…”

Quantum Key Distribution for Critical Infrastructures: Towards Cyber-Physical Security for Hydropower and Dams

“…However, in describing our QKD-for-hydro use case, we note that technologies such as Quantum Digital Signatures (QDS) [ 16 ] and Quantum Secret Sharing (QSS) [ 17 ] play important roles in ensuring communication integrity and the secure distribution of sensitive data among multiple stakeholders, respectively. These modalities, along with Quantum Secure Direct Communication (QSDC) [ 18 , 19 ], provide robust frameworks for safeguarding critical communications. Additionally, the concept of physical layer security, as explored in Rothe’s works [ 20 ], offers another layer of protection by leveraging the physical properties of the communication medium itself to enhance security.…”