On human-centred security: A new systems model based on modes and mode transitions
Edwin J Beggs, John V Tucker, Victoria Wang
TL;DR
The paper presents a human-centred security framework built on modes and mode transitions, formalised with abstract and concrete simplicial complexes to enable geometric visualisation of system beliefs and decisions. It formalises how monitoring data, objectives, and capabilities generate beliefs that drive mode transitions, offering a continuous, explainable view of system behavior via $\Delta_{\mathcal{C}}$ constructions and belief functions. The framework is demonstrated through triage, cyber architectures, and multi-agency critical incident responses such as the UK Gold-Silver-Bronze structure, illustrating benefits like concurrency, independence, continuity, and transparency. This approach advances security analysis and design in human contexts and points toward software tools and rigorous scenario theory as future directions, with broad potential for scenario-based planning across domains.
Abstract
We propose an abstract conceptual framework for analysing complex security systems using a new notion of modes and mode transitions. A mode is an independent component of a system with its own objectives, monitoring data, algorithms, and scope and limits. The behaviour of a mode, including its transitions to other modes, is determined by interpretations of the mode's monitoring data in the light of its objectives and capabilities -- these interpretations we call beliefs. We formalise the conceptual framework mathematically and, by quantifying and visualising beliefs in higher-dimensional geometric spaces, we argue our models may help both design, analyse and explain systems. The mathematical models are based on simplicial complexes.
