A symmetric extensible protocol for quantum secret sharing

TL;DR

This paper presents a new symmetric quantum secret sharing protocol using entanglement, which is secure, extendable to many agents, and allows the spymaster to control when the secret is revealed.

Contribution

It introduces a novel symmetric, extensible quantum secret sharing protocol based on GHZ entanglement with enhanced security and control features.

Findings

Provides unconditional security against eavesdroppers

Supports arbitrary number of agents

Allows spymaster to control secret revelation timing

Abstract

This paper introduces the Symmetric Extensible Quantum Secret Sharing protocol, which is a novel quantum protocol for secret sharing. At its heart, it is an entanglement based protocol that relies on the use of maximally entangled GHZ tuples, evenly distributed among the players, endowing the spymaster with the ability to securely share a secret message with her agents. It offers uncompromising security, making virtually impossible for a malicious eavesdropper or a rogue double agent to disrupt its successful execution. It is characterized by symmetry, since all agents are treated indiscriminately, utilizing identical quantum circuits. Furthermore, it can be seamlessly extended to an arbitrary number of agents. After the completion of the quantum part of the protocol, the spymaster will have to publicly transmit some information, in order to enable the agents to discover the secret message. Finally, it has the additional advantage that the spymaster has the privilege to decide when it is the right time for the agents to discover the secret message.