Expirationbased

Expirationbased is a term used to describe systems and mechanisms that determine validity and access based on an expiration timestamp. In such schemes, entitlements, tokens, licenses, or cached data include a defined expiry date or duration, after which they become invalid unless renewed or extended.

Common implementations include time-limited API tokens (for example, a JWT with an exp claim), software licenses that transition to disabled when the license date passes, and digital content or subscriptions that unlock access only within a designated window. Caching systems also use expiration, assigning a time-to-live (TTL) after which stored items are considered stale and are refreshed.

Operational considerations: reliable time sources are essential; clock skew between client and server can cause premature expiration or overlong validity. Entities may implement grace periods, re-issue flows, or a separate revocation mechanism for urgent invalidation. For offline scenarios, tamper-resistant clocks or locally verifiable expiry data may be used.

Advantages include automatic invalidation, reduced need for constant revocation checks, and predictable access control. Drawbacks include potential service disruption due to expiry, dependence on time synchronization, and challenges around renewing or extending expiry without user friction.

Common domains include software licensing, API authentication, streaming and e-book services, password reset links, and content licensing. See also token expiration, time-to-live, license management, access control, DRM, and JWT.