The zero trust model replaces which security design principle?

The zero trust model fundamentally challenges the traditional notion of security by adopting the principle of "never trust, always verify." This is a significant shift from the "trust but verify" philosophy, which presumes that entities, once authenticated, can be trusted to access systems and data. In contrast, the zero trust approach assumes that threats could exist both outside and inside the network, and therefore, verification is required for every access request, regardless of the origin.

By replacing the idea of trusting previously authenticated entities, the zero trust model implements a more stringent access control mechanism, focusing on continuous authentication and strict validation of user identities and devices. It also emphasizes the importance of micro-segmentation and ensuring that users only have access to the resources necessary for their roles, thus enhancing overall security posture. This model is particularly relevant in modern computing environments where perimeter defenses are less effective due to cloud services and remote work arrangements.