An arbitrated quantum signature scheme for classical information using entanglement swapping

Quantum signature protocols often rely on quantum states to carry signature information directly. However, they need SWAP tests, which require numerous copies to ensure accuracy and security, resulting in high implementation costs. This study proposes an arbitrated quantum signature protocol that incorporates classical information with entanglement swapping. Quantum states are converted into classical information immediately after measurement. The protocol does not rely on SWAP tests, avoids long-term storage of quantum signatures, and employs exclusive-OR operations and hash functions to process signature data. By leveraging a third-party arbitrator, it enables reliable identity verification of the signer and verifier, thereby guaranteeing unforgeability and nonrepudiation.