Generalized Controlled Quantum Secure Communication using GHZ-like state

TL;DR

This paper introduces a new controlled quantum secure communication scheme using GHZ-like states, enhancing security and efficiency, and generalizing to multiple controllers with entanglement swapping.

Contribution

It proposes a novel CQSC protocol with improved security and efficiency, and extends the scheme to include multiple controllers through entanglement swapping.

Findings

Scheme is immune to common eavesdropping attacks

Uses dense coding to increase qubit efficiency

Can be generalized to N controllers with shared GHZ-like states

Abstract

We present a novel scheme for controlled quantum secure communication (CQSC) using GHZ-like state. In this scheme, a trusted controller assists the users for achieving secure transmission of data between them. The dense coding technique is exploited to increase the qubit efficiency and we show that the proposed scheme is immune against common eavesdropping attacks. We show how the method can be generalized to include N controllers using sets of GHZ-like states shared among the controllers and users. In this process entanglement swapping and single particle measurements are performed by the controllers to relax their controls and the users get entangled in Bell states.