Approximate quantum state sharing via two private quantum channels

TL;DR

This paper presents a secure approximate quantum state sharing protocol using random unitary channels that maintains information-theoretic secrecy while reducing classical key requirements.

Contribution

It introduces a novel approximate quantum state sharing scheme based on random unitary channels that enhances security and efficiency over existing methods.

Findings

Protocol is secure against external and internal attackers.

It reduces classical secret key requirements.

Maintains information-theoretic secrecy despite small information leakage.

Abstract

We investigate the approximate quantum state sharing protocol based on random unitary channels, which is secure against any exterior or interior attackers in principle. Although the protocol leaks small information for a security parameter $\epsilon$, the scheme still preserves its information-theoretic secrecy, and reduces some pre-shared classical secret keys for a private quantum channel between a sender and two receivers. The approximate private quantum channels constructed via random unitary channels play a crucial role in the proposed quantum state sharing protocol.