Access Control List

Access Control List: A list of rules that permits or denies access to resources. The control applies to network communicationNetwork CommunicationThe exchange of data between systems over network protocols and connections. or network accessNetwork AccessThe ability of a user, device, or workload to connect to and use network resources.. Effectiveness is achieved through restrictive rules, segmentation, continuous monitoringMonitoringThe continuous observation of systems, identities, networks, and controls for relevant changes., and coordinated response processesResponse ProcessA coordinated sequence of decisions and actions for handling security events and incidents..

How it works and where it fits

Access Control List separates the subject, digital identity, authentication factor, and authorization decision. Authentication establishes who or what is presenting an identity; authorization then determines which action is permitted in the current context. Session state, device trust, request origin, and risk signals can further influence that decision.

Practical security relevance

Effective implementation requires a controlled identity lifecycle from creation through role and entitlement changes to suspension and removal. Strong authentication, least privilege, periodic recertification, and traceable logs are central. Controls must also identify abuse of legitimate accounts, because valid credentials alone do not prove that an action is legitimate.

Related concepts

• Access ControlAccess ControlGoverns who is permitted to access specific systems, data, or functions.: Governs who is permitted to access specific systems, data, or functions.
• FirewallFirewallControls network traffic based on defined rules and security policies.: Controls network traffic based on defined rules and security policies.
• Network SegmentationNetwork SegmentationSeparates network segments to control access and limit lateral movement.: Separates network segments to control access and limit lateral movement.
• AuthorizationAuthorizationDecision regarding which actions an authenticated identity is permitted to perform.: Decision regarding which actions an authenticated identity is permitted to perform.