Background: The contemporary landscape of user authentication is evolving rapidly as mobile devices, cloud services, and agentic artificial intelligence converge. Traditional reliance on single-factor credentials and static, perimeter-based security models has proven inadequate for resisting sophisticated attacks and for preserving privacy and usability in ubiquitous computing environments (Jakobsson, 2009; Abowd et al., 2000). Contemporary work emphasizes context-aware authentication, continuous and implicit methods, and zero-trust principles, yet there remains a gap in integrating explainability, device integrity mechanisms, and enterprise device management constructs into a unified identity architecture that supports both human and machine (agentic) actors (Hayashi et al., 2013; Badal Bhushan, 2025).

Methods: This article presents a theoretically grounded design for an explainable zero-trust identity architecture that fuses context-aware continuous authentication techniques, device attestation and integrity (including operating-system level protections such as system integrity mechanisms and disk encryption), enterprise device provisioning and management, and privacy-aware explainable decisioning for authentication and access decisions. The methodology is a conceptual synthesis: we systematically analyze the reference corpus provided, extract design primitives and threat models, and then elaborate an architectural blueprint that maps primitives to operational components, authentication flows, and explanation-generation modules. The work adopts rigorous evaluative criteria (security, privacy, usability, scalability, and explainability) and applies them descriptively to anticipated deployments.

Results: The architecture integrates eight functional components—Context Sensing, Behavioural Profiling, Device Integrity Attestation, FIDO-style Public Key Authentication, Continuous Risk Engine, Explanation Generator, Enterprise Management Bridge, and Audit and Recovery Services—and specifies interfaces, data flows, and trust anchors. The design articulates how device features such as FileVault encryption (Apple, 2023a), System Integrity Protection (Apple, 2023b), and backup/restore considerations (Apple, 2023c) affect attestation and key-protection strategies. It further explains how message interception risks (Shah, Jeong & Doss, 2021) and second-factor device-mirroring threats motivate minimizing SMS usage and favoring device-bound cryptographic authenticator approaches (Shah & Kanhere, 2018).

Conclusion: By systematically combining context awareness, continuous implicit authentication, device attestation, enterprise management, and explainability, the proposed zero-trust identity architecture addresses many contemporary deficiencies in authentication ecosystems. The paper articulates implementation guidance, nuance on privacy trade-offs, counter-arguments, and a research agenda for empirical evaluation and standardization. The architecture aims to be extensible to both human users and machine agents, promoting resilient, transparent, and privacy-respecting authentication in hybrid modern IT environments (Hayashi et al., 2013; Badal Bhushan, 2025).