Authenticated Semi-quantum Direct Communication Protocols using Bell States

TL;DR

This paper introduces two novel authenticated semi-quantum direct communication protocols that operate without classical channels, enabling secure message transmission and verification with high detection probability using Bell states.

Contribution

It presents the first ASQDC protocols that do not require classical channels and are resistant to common attacks, utilizing pre-shared keys and Bell states.

Findings

Protocols detect single-qubit modifications with near certainty

No classical channel needed for communication

Resistant to well-known quantum attacks

Abstract

This study presents the first two authenticated semi-quantum direct communication (ASQDC) protocols without using any classical channel. By pre-sharing the master secret key between two communicants, a sender with advanced quantum devices can transmit a secret message to a receiver who can only perform classical operations without any information leakage. The receiver is then capable of verifying the message up to the single qubit level, i.e., a one-qubit modification of the transmitted quantum sequence can be detected with a probability close to 1. Moreover, the proposed protocols are resistant to several well-known attacks.