Zero-trust authentication is an approach that verifies a requester’s identity before granting access, rather than assuming it is trustworthy because it is inside a network or has connected before. Verification may use credentials, multifactor checks, certificates, or workload identity. Authentication establishes who or what is requesting access; authorization separately determines which resources and actions are permitted.
In cyber security, this helps limit damage from stolen credentials, compromised devices, and impersonated services. For AI agents and other machine workloads, defenders can assign distinct identities, link them to responsible owners, and verify them when they request access. Permissions should then be narrowly scoped and activity logged. Authentication alone does not make an agent safe: excessive permissions or untrusted outputs require separate controls.