Leidim

Leidim is a theoretical concept in access control and authorization used in discussions of distributed systems and cloud computing. It denotes a minimal, time-bounded permission token that authorizes a holder to perform a specific action on a defined resource within a specified scope.

Origin and terminology: The term has appeared in academic and industry discussions as an umbrella for lightweight, auditable permissions that are easier to issue and revoke than large role-based assignments. It is not tied to a single standard, and implementations vary by domain.

Mechanism: A leidim token encodes the actor, the target resource, the permitted action, a validity window, and delegation rules. Tokens are typically cryptographically signed by an authorization service and presented to a resource server. Verification is often stateless, relying on a public key or shared secret. Revocation is supported via short lifetimes, revocation lists, or immediate invalidation signals.

Relation to other models: Leidim emphasizes narrow scope and brevity of validity in contrast to broad role assignments. It shares cryptographic verification with capability-based security but emphasizes centralized issuance and auditability akin to token-based systems.

Applications: Used in microservice architectures, cloud resource management, API gateways, and IoT ecosystems to grant temporary access without issuing long-lived credentials. Example: a service is permitted to read a user profile for 15 minutes.

Limitations: Requires clock synchronization, robust key management, and timely revocation propagation. If tokens are leaked, access can be misused until expiry.

See also: Access control, capability-based security, tokens, OAuth, ACLs, RBAC.