Verifier-initiated quantum message-authentication via quantum zero-knowledge proofs
On-demand authentication is critical for scalable quantum systems, yet current approaches require the signer to initiate communication, creating unnecessary overhead. We introduce a new method where the verifier can request authentication only when needed, improving efficiency for quantum networks and blockchain applications. Our approach adapts the concept of zero-knowledge proofs widely used in classical cryptography to quantum settings, ensuring that verification reveals nothing about secret keys. We develop a general framework that converts any suitable quantum proof into a verifier-driven signature protocol and present a concrete implementation based on quantum measurements. The protocol achieves strong security guarantees, including resistance to forgery and privacy against curious verifiers, without relying on computational hardness assumptions and with qubit technologies. This work delivers the first general verifier-initiated quantum signature scheme with formal security, paving the way for scalable, secure authentication in future quantum infrastructures and decentralized systems.