What it is
Access control is the discipline of defining who or what can interact with a resource, under which circumstances, using which methods, and with what level of authority. In practice it combines policies, procedures, and technical enforcement mechanisms that guard applications, infrastructure, and data stores against misuse. A complete access control model balances authentication, authorization, and accountability: users and services must prove their identity, receive least-privilege entitlements, and leave auditable trails of their activity. Modern enterprises weave together discretionary, mandatory, and role-based models while increasingly adopting attribute-based rules that account for contextual signals like device health or network location. These controls stretch across identity providers, directory services, cloud platforms, SaaS applications, and on-premises systems. When implemented well, access control becomes a dynamic, risk-aware perimeter that aligns business productivity with cyber defense. When neglected, it creates a silent sprawl of excessive privileges and shadow accounts that turn routine incidents into crippling breaches.
Why it matters
Most breaches rely on stolen or abused credentials. Effective access control reduces the blast radius of inevitable compromises, limits lateral movement, and demonstrates compliance with frameworks like ISO 27001, SOC 2, HIPAA, and PCI DSS. It also enables faster incident response because investigators can rely on consistent entitlements and central logging.
How to reduce risk
- Establish a centralized identity provider and enforce single sign-on for all business-critical systems.
- Apply the principle of least privilege with time-bound, reviewable entitlements and automated revocation workflows.
- Require multi-factor authentication for privileged actions and high-risk contexts.
- Continuously monitor and remediate orphaned accounts, inactive roles, and policy drift across environments.