Main Content

ZTOEI – An Assessment Framework for Efficient Zero-Trust Deployment in Single- and Nested-Cluster Environments

Author: Steffen Jahn

Supervisors: Prof. Dr. Boris Koldehofe, Dr.-Ing. Peter Amthor

Format: Master's thesis, TU Ilmenau

This thesis develops the Zero-Trust Operational Efficiency Index (ZTOEI), a quantitative framework that relates security benefits to operational costs in cloud-based deployments. Existing Zero-Trust evaluations remain largely qualitative or focus on individual mechanisms such as service meshes, micro-segmentation, or attestation, without providing a unified basis for comparing whole architectures. The index combines seven orthogonal components (isolation strength, attestation coverage, attacker mobility, system exposure, performance overhead, operational complexity, and trusted computing base size) into a single benefit-cost ratio. The framework is applied to four reference scenarios: single-cluster and nested-cluster deployments, each with and without Zero-Trust enforcement. A representative three-tier application is deployed in each scenario, and the seven components are measured directly. The experimental results match the theoretical predictions in each scenario. Full Zero-Trust adoption justifies its operational cost in the single-cluster case, but not in nested deployments. Structural separation through nesting activates the trusted computing base multiplier without, by itself, unlocking the security gains that justify it. The framework therefore characterises Zero-Trust adoption as a question of which mechanisms are deployed, rather than whether the architecture is nested.

References: https://bibliographie.tu-ilmenau.de/servlets/DozBibEntryServlet?mode=show&id=ilm_mods_00080347&lang=en