Quantum identity authentication protocol based on flexible quantum homomorphic encryption with qubit rotation

Quantum identity authentication (QIA) ensures that entities of quantum communication will not be impersonated by attackers. As an auxiliary protocol, an ideal QIA protocol cannot take up too many quantum resources and needs to be embedded in the original protocol to enhance security. In this paper, we propose a flexible ternary quantum homomorphic encryption (QHE) protocol using qubit rotation and indicate that the QHE framework can be used to design QIA protocols. The ternary QIA protocol based on QHE can be embedded in the original protocol because both protocols use the same quantum resources. The proposed protocol uses different vouchers from previous protocols, allowing it to prevent various types of attacks and performs well in terms of communication efficiency. The QHE framework can benefit other quantum cryptographic fields.