Authentication _verified_ Online

Physical items like security tokens, smart cards, or a mobile phone used for SMS codes or authenticator apps.

A single factor (e.g., password alone) is and is dangerously weak. Two different factors constitute two-factor authentication (2FA) ; three is multi-factor authentication (MFA) . The key is different categories : a password (knowledge) plus a one-time code from a phone (possession) is true 2FA. A password plus a security question is still just knowledge—one factor, twice.

After login, the server issues a signed session ID (cookie). The browser sends it with each request. Stateless on the client, but the server must store session state. Vulnerable to session hijacking if cookies are not HttpOnly , Secure , and SameSite . authentication

It is distinct from , which answers the question: "Are you allowed to do this?" (Authentication verifies identity; Authorization verifies permissions).

In computer systems, (often shortened to "auth") is the critical first layer of security used to verify that a person or entity is who they claim to be. This process is distinct from authorization , which determines what an authenticated user is actually allowed to do. The Three Factors of Authentication Physical items like security tokens, smart cards, or

In the digital realm, identity is the most valuable—and most vulnerable—asset. Before a system can decide what you are allowed to do (authorization), it must first establish who you are. This foundational process is : the verification of a claimed identity.

Behind every login screen are standardized protocols that manage the exchange of credentials. These are the unsung workhorses. The key is different categories : a password

Authentication is the first and most critical decision point in security. It is a balancing act: strong enough to resist determined attackers, yet frictionless enough that users don't subvert it. The trajectory is clear: passwords as the primary factor are ending. The future belongs to —passkeys and WebAuthn—augmented by risk-based continuous checks.