# Cryptanalysis and improvement of dynamic quantum secret sharing protocol based on two-particle transform of Bell states

## TL;DR

This paper analyzes the security flaws of a quantum secret sharing protocol based on Bell states, demonstrating its vulnerabilities to collusion and proposing an improved version to enhance security.

## Contribution

The paper identifies security weaknesses in a prior quantum secret sharing protocol and offers a novel improvement to prevent dishonest agent collusion.

## Key findings

- The original protocol is vulnerable to collusion by dishonest agents.
- The authors demonstrate how colluding agents can access secret messages.
- An improved protocol is proposed to mitigate security risks.

## Abstract

In this paper [Chin. Phys. B 27 (2018) 080304], Du and Bao proposed a quantum secret sharing protocol based on two-particle transform of Bell states. We study the security of the proposed protocol and find that it is not secure, that is, the two dishonest agents, Bob and Zach, can collude to obtain Alice's secret messages without the help of the other agents. Finally, we give a possible improvement of the proposed protocol.