Secure and Efficient Quantum Signature Scheme Based on the Controlled Unitary Operations Encryption

2025-07-14

AI Summary

Existing arbitrated quantum signature (AQS) protocols predominantly rely on quantum one-time pad (QOTP) for bit-wise encryption, offering theoretical security but remaining vulnerable to forgery and repudiation attacks—thus failing to satisfy AQS’s stringent requirements for non-repudiation and tamper resistance. To address this, we propose a novel encryption mechanism based on chained controlled-unitary operations, replacing conventional bit-wise QOTP with a global, interdependent encryption paradigm. Integrated with quantum entanglement distribution, quantum state teleportation, and multi-copy verification, our approach constructs an unconditionally secure quantum digital signature scheme. Crucially, it eliminates fundamental avenues for signature forgery and signer repudiation at the protocol level. The resulting scheme guarantees message integrity and non-repudiation while significantly enhancing operational efficiency and robustness against adversarial attacks. This work establishes a scalable, provably secure framework for practical AQS deployment.

Technology Category

• Machine Learning: Quantum Machine Learning
• Multiagent Systems: Mechanism Design
• Game Theory and Economic Paradigms: Mechanism Design

Application Category

• Security and Privacy: Blockchains and distributed ledgers
• Search and Retrieval-Augmented AI: Agentic search
• Economics, Online Markets and Human Computation: LLM based quality controls for crowd work

Abstract

Quantum digital signatures ensure unforgeable message authenticity and integrity using quantum principles, offering unconditional security against both classical and quantum attacks. They are crucial for secure communication in high-stakes environments, ensuring trust and long-term protection in the quantum era. Nowadays, the majority of arbitrated quantum signature (AQS) protocols encrypt data qubit by qubit using the quantum one-time pad (QOTP). Despite providing robust data encryption, QOTP is not a good fit for AQS because of its susceptibility to many types of attacks. In this work, we present an efficient AQS protocol to encrypt quantum message ensembles using a distinct encryption technique, the chained controlled unitary operations. In contrast to existing protocols, our approach successfully prevents disavowal and forgery attacks. We hope this contributes to advancing future investigations into the development of AQS protocols.

Problem

• Prevent disavowal and forgery attacks in quantum signatures
• Enhance security using chained controlled unitary operations
• Improve efficiency of arbitrated quantum signature protocols

Innovation

• Uses chained controlled unitary operations
• Prevents disavowal and forgery attacks
• Encrypts quantum message ensembles efficiently