Which cybersecurity principle involves not trusting any entity by default?

The principle that involves not trusting any entity by default is Zero Trust Security. This cybersecurity approach is built on the premise that threats could be internal or external, and therefore, every access request, regardless of its origin, must be verified before granting permission.

Zero Trust Security assumes that a breach is inevitable or has already occurred, which necessitates strict access controls and continuous monitoring of users and devices. By requiring authentication and authorization for every attempt to access resources, organizations can significantly reduce the risk of unauthorized access and protect sensitive information.

This principle contrasts with traditional security models that often operate on the idea that once users are inside the network, they can be trusted with minimal oversight. However, Zero Trust recognizes that this can lead to vulnerabilities and emphasizes a more rigorous security posture across all levels of access.

Other concepts like Data Privacy, Endpoint Security, and Multi-Factor Authentication, while important in their own right, do not encapsulate the fundamental tenet of Zero Trust Security where default trust is actively challenged and eliminated. Data Privacy focuses on the proper handling of sensitive data, Endpoint Security refers to measures taken to protect endpoints like computers and mobile devices, and Multi-Factor Authentication adds layers to the authentication process but doesn't necessarily negate default trust assumptions on its own.