Quantum digital signature based on single-qubit without a trusted third-party

TL;DR

This paper introduces a new quantum digital signature protocol that eliminates the need for a trusted third-party, leveraging quantum one-way functions and quantum states to enhance security and practical applicability.

Contribution

It presents a novel quantum digital signature scheme that removes reliance on trusted third-parties, using quantum one-way functions and ensuring information-theoretic security.

Findings

The protocol achieves information-theoretical unforgeability.

It satisfies asymmetry, undeniability, and expandability.

No trusted third-party is required in the scheme.

Abstract

Digital signatures are a powerful cryptographic tool widely employed across various industries for securely authenticating the identity of a signer during communication between signers and verifiers. While quantum digital signatures have been extensively studied, the security still depends on a trusted third-party. To address this limitation and enhance the applicability in real-world scenarios, here we propose a novel quantum digital signature protocol without a trusted third-party to further improve the security. We note that a quantum one-way function can work appropriately in digital signature due to the intrinsic non-cloning property for quantum states. Secret keys in the protocol are constituted by classical private keys and quantum public keys because we assume that no user is trusted in the protocol. We prove that the protocol has information-theoretical unforgeability. Moreover, it satisfies other important secure properties, including asymmetry, undeniability, and expandability.