Quantum Message Authentication Code Independent of Computational Difficulty

The rise of quantum computing poses significant challenges to security systems, with traditional message authentication codes (MACs) at unprecedented risk of compromise. This paper proposes a quantum message authentication code (QMAC) leveraging quantum mechanics to achieve robust security. The QMAC uses quantum one-way functions (QOWFs) to convert encrypted classical bits into qubits. This approach fundamentally differs from the computational hardness assumptions of conventional MACs. The QMAC's security is computationally difficulty-independent based on the inherent properties of quantum mechanics, making it impervious to exhaustive search attacks. Additionally, the protocol integrates authentication directly into the secure communication framework, obviating the need for extra particles and reducing computational complexity compared to stabilizer code-based or controlled unitary operations. Through a rigorous security analysis, we demonstrate the resilience of the proposed QMAC protocol against a wide range of adversarial strategies, including interception-resend attacks, identity impersonation, and entanglement-based attacks, among others.