A Practical Semi-Quantum Signature Protocol with Improved Eavesdropping Detection

TL;DR

This paper introduces a practical semi-quantum signature protocol utilizing Bell states, with enhanced eavesdropping detection and security against signature tampering, requiring only the signer to have full quantum capabilities.

Contribution

It presents a semi-quantum signature scheme that reduces quantum requirements for participants and improves security through better tampering detection.

Findings

Protocol effectively detects eavesdropping and tampering.

Designed to be practical with only the signer needing full quantum capability.

Maintains security even if signatures are tampered with after generation.

Abstract

Semi-quantum signature (SQS) schemes aim to enable quantum signature functionality in scenarios where only a subset of participants possess full quantum capabilities, thereby improving practical deployability while preserving quantum security advantages. Within this framework, we present a practical SQS protocol based on Bell states. The protocol is designed so that only the signer requires full quantum capability, significantly alleviating the quantum burden on the remaining participants. To strengthen security in semi-quantum environments, we incorporate an improved eavesdropping-detection mechanism that more effectively detects tampering. Compared with many existing schemes, which do not explicitly consider tampering of already generated signatures in their unforgeability analyses, the proposed protocol is designed to remain secure in the presence of such tampering.