Bidirectional relationships: The Diamond Model emphasizes the interconnected and bidirectional nature of the relationships between the four core features: Adversary, Capability, Infrastructure, and Victim. Information flows in both directions between these elements. For example, the adversary uses infrastructure, but the infrastructure also reveals information about the adversary. Also, insights about the victim can help refine detection of the infrastructure or understanding of the adversary. This interplay is a key characteristic of the model.
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Causality chains: While causality can be inferred from the relationships within the Diamond Model, the model itself doesn't explicitly define or focus on linear causality chains. The focus is on the relationships themselves, which can be complex and intertwined, not necessarily sequential cause-and-effect.
Adversary capability: Adversary capability is one of the four core components of the Diamond Model, but it doesn't define the interaction between all four. The question asks about the concept defining the interaction.
Operational control: Operational control is related to the adversary's actions and infrastructure, but it's not the fundamental concept that defines the interaction between all four elements of the Diamond Model. It's more specific to the adversary's perspective.