# An Efficient and Secure Semi-Quantum Secret Sharing Scheme Based on W State Sharing of Specific Bits

## TL;DR

This paper introduces a secure and efficient quantum-based secret sharing method using W states for scenarios with limited quantum resources.

## Contribution

A novel semi-quantum secret sharing protocol using W states and decoy photons to resist various attacks.

## Key findings

- The protocol's detection probability for intercept–resend attacks increases exponentially with decoy photons.
- Entanglement–measurement attacks cause detectable disturbances in the quantum state.
- Double CNOT attacks are neutralized by position untraceability and mixed-basis strategies.

## Abstract

This paper presents a semi-quantum secret sharing (SQSS) protocol based on three-particle W states, designed for efficient and secure secret sharing in quantum-resource-constrained scenarios. In the protocol, a fully quantum-capable sender encodes binary secrets using W, while receivers with limited quantum capabilities reconstruct the secret through collaborative Z basis measurements and classical communication, ensuring no single participant can obtain the complete information independently. The protocol employs a four-state decoy photon technique ({|0〉,|1〉,|+〉,|−〉}) and position randomization, combined with photon number splitting (PNS) and wavelength filtering (WF) technologies, to resist intercept–resend, entanglement–measurement, and double controlled-NOT(CNOT) attacks. Theoretical analysis shows that the detection probability of intercept–resend attacks increases exponentially with the number of decoy photons (approaching 1). For entanglement–measurement attacks, any illegal operation by an attacker introduces detectable quantum state disturbances. Double CNOT attacks are rendered ineffective by the untraceability of particle positions and mixed-basis strategies. Leveraging the robust entanglement of W states, the protocol proves that the mutual information between secret bits and single-participant measurement results is strictly zero, ensuring lossless reconstruction only through authorized collaboration.