Device trust is a security decision about whether an endpoint, such as a laptop, phone, or server, is allowed to access sensitive resources. It is usually based on signals like device health, management status, encryption, patch level, and whether the endpoint matches policy. In a Zero Trust design, identity alone is not enough; the system also asks, “Can this device be trusted right now?”
This matters because attackers often use valid accounts from risky or compromised devices. A stolen password may authenticate successfully, but an unmanaged or infected endpoint can still expose data or privileged systems. Defenders use device trust to block or limit access, require stronger checks, or force remediation before granting a session. In practice, it helps detect cases where a real user logs in from a machine that no longer meets security standards.