Zero Trust Architecture in Modern Networks: A Systematic Literature Review and Future Research Directions

Abstract

Transition from a perimeter network security approach to an identity-focused and data-driven one has driven the rapid growth of Zero Trust Architecture (ZTA). This study offers an exhaustive Systematic Literature Review (SLR) based on PRISMA methodology examining 90 peer-reviewed articles about ZTA design, implementation, and evaluation published between 2017 and 2024 in the context of contemporary enterprise, cloud, 5G, and Internet-of-Things (IoT) networks. We summarize findings on ZTA across seven ZTA pillars: Identity, Devices, Networks, Workloads, Data, Visibility and Analytics, and Automation; we also observe a high convergence towards the Never Trust, Always Verify principle and substantial variation in the deployment maturity and evaluation quality of ZTA solutions. A taxonomy of ZTA frameworks (NIST SP 800-207, CISA, BeyondCorp, DISA) and quantitative benchmarking of ZTA capabilities with mathematical trust score formulations are provided. Analysis highlights consistent research gaps on quantum-resistant ZT cryptography, automated policy adaptation, federated ZT across jurisdictions, and ZT in OT environments. We conclude the paper with the prioritized research agenda and recommendations for deployment of ZTA. Global market for ZTA will grow to USD 165.8 billion by 2028 from its value of USD 66.8 billion in 2024 (CAGR 19.2%).