In Palo Alto Networks' security framework, what does "Zero Trust" mean?

Zero Trust is a security model that fundamentally shifts the approach to security by assuming that no user or device should be trusted by default, regardless of whether they are inside or outside of an organization's network perimeter. The essence of this principle lies in continuous verification and validation of users and devices before granting access to resources.

Under the Zero Trust framework, every request for access must be authenticated, authorized, and encrypted. This means that even if a user is inside the network, they still need to prove their identity and ensure that their device meets security standards before being granted access to sensitive data or applications. This approach mitigates risks associated with insider threats and compromised credentials, as it does not automatically trust any entity.

The other options do not encapsulate the Zero Trust philosophy; for instance, allowing all traffic by default contradicts the core premise of the model. Similarly, while access being granted only to known devices may align with Zero Trust practices, it doesn't capture the model's foundational principle of mistrust towards all users and devices initially. Monitoring connections for performance, while beneficial, is not a defining characteristic of Zero Trust itself.