Which security model relies on the assumption that everything on the internal network can be trusted?

The perimeter-based security model, often metaphorically referred to as 'castle-and-moat,' focuses on building strong defenses at the network edge to keep external threats out. This model operates under the assumption that once a user or device is inside the network perimeter, it can be implicitly trusted to access internal resources.

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven distinct layers, not a security trust model.

The Cloud Computing model describes different ways computing resources are delivered and consumed over the internet (e.g., IaaS, PaaS, SaaS), rather than a specific security trust philosophy.

The Zero Trust security model explicitly rejects the idea of inherent trust, enforcing the principle of 'never trust, always verify' for all access attempts, regardless of location or previous authentication.