A Quantum-Memory-Free Quantum Secure Direct Communication Protocol Based on Privacy Amplification of Coded Sequences

TL;DR

This paper introduces a quantum secure direct communication protocol that eliminates the need for quantum memory by using privacy amplification techniques on coded sequences, providing a practical alternative to traditional quantum key distribution.

Contribution

The paper presents a novel QMF-QSDC protocol relying solely on universal hashing and develops privacy amplification theorems for secure classical sequences against quantum side-information.

Findings

Protocol achieves secure communication without quantum memory.

Privacy amplification theorems enable secrecy extraction from coded sequences.

Framework facilitates design of effective QMF-QSDC protocols.

Abstract

We develop an information-theoretic analysis of Quantum-Memory-Free (QMF) Quantum Secure Direct Communication (QSDC) under collective attacks as an alternative to the use of a conventional Quantum Key Distribution (QKD) protocol in conjunction with one-time pads. Our main contributions are: 1) a QMF-QSDC protocol that only relies on universal hashing of coded sequences without wiretap coding; 2) a set of privacy amplification theorems for extracting secrecy from coded classical sequences against quantum side-information. These tools open the way to the design of effective QMF-QSDC protocols.