The Enterprise Security Architecture for Reliable ICT Services (ESARIS) is a reference architecture for protecting ICT services [EvFWB12]. User organizations are enabled to compare offerings and assess risks. ICT service providers receive a comprehensive template for implementing and maintaining all security measures, including those relating to service management. The architecture also introduces a Security Taxonomy on Level 4 of its hierarchy of security standards. This taxonomy is explained in this paper. The structure or organization model assigns security measures to production areas. It considers state-of-the-art service management processes (ITIL) and integrates ICT security management and IT service management. The taxonomy supports division of labor and assignment of responsibility within a large-scale ICT production. The taxonomy is compatible with all types of ICT services and service models since it allows easy identification and selection of the relevant security documentation. The taxonomy is modular and derived from specific criteria. The latter result from challenges in day-to-day business and consider interests and requirements both from user organizations and from ICT service providers.
