Before revision:  We have systematically studied such threats from models, methods, experiments , evaluations, and defenses . Specifically, first, we conducted a formal definition and security attribute research on UBM. We proposed two key characteristics that must be met in order to achieve "unbreakable" security attributes and their corresponding evaluationquaternions.
After revision:  We have systematically studied such threats from models, methods, experiments , evaluations, and defenses . Specifically, we first formalized the definition of UBM and analyzed its security attributes, put forward two core features that are essential for realizing the "unbreakable" security attributes and their corresponding evaluationquaternions.