authenticated

Authenticated is an adjective used to indicate that the claimed identity of a person, device, or data item has been verified by a trusted authority. In information security, authentication is the process of proving that someone or something is who or what it claims to be. This is distinct from authorization, which determines what resources an authenticated identity is permitted to access.

Authentication methods can be knowledge-based (passwords or PINs), possession-based (security keys, tokens), or inherent (biometrics such as fingerprints or facial recognition). Modern systems often use multi-factor authentication, combining two or more factors. Public key infrastructure and cryptographic challenges enable certificate-based and device-based authentication. Hardware security keys (FIDO2/WebAuthn) offer phishing-resistant authentication. After successful authentication, a system may issue a session token or cryptographic proof of identity.

In communications and software, authenticated data or messages are those whose source is verified, and whose integrity is protected against tampering. Sessions are typically authenticated to bind actions to a verified identity. Common protocols include HTTP authentication schemes, OAuth 2.0 and OpenID Connect for identity assertion, and Kerberos in enterprise networks. In many services, authentication is the first step before authorization, auditing, and access control.

Security considerations include protecting credentials, resisting phishing, handling token lifetimes and revocation, and ensuring resistance to replay attacks. The term authenticated is used to describe a successful outcome of the authentication process; if verification fails, the subject is unauthenticated. Ongoing risk management often combines authentication with ongoing verification and behavior analytics to detect compromised accounts.