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Reference

Glossary

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A

ABAC

Attribute-Based Access Control. Access decisions based on attributes—of the user, the resource, the environment—rather than just roles. More flexible than RBAC, but more complex to manage without the right tooling.

Related:RBACPBACAuthorization

Access Control

The process of determining and enforcing what actions users can perform on resources. Encompasses both authentication (who are you?) and authorization (what can you do?).

Related:AuthorizationAuthentication

Access Review

A periodic audit process where managers or resource owners verify that users still need the access they have. Often required for compliance but frequently becomes a checkbox exercise without proper authorization infrastructure.

Related:Least PrivilegeCompliance

Authentication

The process of verifying identity—proving you are who you claim to be. Typically handled by identity providers through SSO, MFA, passwords, or other credentials. Distinct from authorization.

Related:AuthorizationSSOIdP

Authorization

Deciding what a user can do—what resources they can access, what actions they can take, under what conditions. The "gap" in most organizations' security architecture.

Related:AuthenticationAccess ControlPBAC

Authorization Debt

The accumulated cost of ad-hoc authorization decisions: hardcoded permissions, role sprawl, inconsistent policies across apps. Like technical debt, it compounds over time and becomes increasingly expensive to address.

Related:Role ExplosionPolicy Sprawl

C

Coarse-Grained Authorization

Access control at a high level—typically whether a user can access an application or feature at all. Contrast with fine-grained authorization, which controls access to specific resources or data.

Related:Fine-Grained AuthorizationRBAC

Compliance

Adherence to regulatory requirements (HIPAA, SOX, GDPR, etc.) that often mandate specific access control capabilities like least privilege, audit trails, and access reviews.

Related:Audit TrailLeast PrivilegeAccess Review

Context-Aware Authorization

Access decisions that factor in real-time context: device type, location, time of day, risk score. A key capability for zero-trust architectures.

Related:Zero TrustABACReal-Time Authorization

D

Decision Log

A record of authorization decisions—who requested access, to what, when, and why the decision was granted or denied. Essential for compliance and incident investigation.

Related:Audit TrailCompliancePDP

E

Entitlement

A permission or access right granted to a user. Managing entitlements at scale is one of the core challenges of enterprise authorization.

Related:PermissionRoleAccess Control

Externalized Authorization

Moving access control logic out of application code and into a dedicated policy layer. The application asks "can this user do this?" and gets an answer, rather than calculating it internally.

Related:PDPPEPPolicy-Based Access Control

F

Fine-Grained Authorization

Access control at a granular level—specific records, fields, or operations. "Can this user see this specific customer's data?" rather than "Can this user access the CRM?"

Related:Coarse-Grained AuthorizationRow-Level SecurityABAC

I

IdP

Identity Provider. A service that manages user identities and handles authentication. Examples include Okta, Azure AD, and Auth0. IdPs handle who you are; authorization handles what you can do.

Related:AuthenticationSSOSAML

J

Just-In-Time Access

Granting access only when needed and automatically revoking it after a set period. Reduces standing privileges and supports least privilege principles.

Related:Least PrivilegeZero Standing Privileges

L

Least Privilege

The principle that users should have only the access they need, nothing more. Easy to say, hard to prove without fine-grained authorization and proper audit capabilities.

Related:ComplianceZero TrustAccess Review

O

OPA

Open Policy Agent. An open-source, general-purpose policy engine that uses Rego as its policy language. Powerful but requires significant investment to build a complete authorization platform around it.

Related:RegoPolicy EngineExternalized Authorization

P

PBAC

Policy-Based Access Control. Access decisions driven by policies that can incorporate roles, attributes, context, and business rules. More expressive than RBAC or ABAC alone.

Related:RBACABACPolicy

PDP

Policy Decision Point. The component that evaluates policies and returns access decisions. The "brain" of an authorization system. Can be centralized or distributed.

Related:PEPPolicy EngineExternalized Authorization

PEP

Policy Enforcement Point. The component that enforces access decisions—typically in the application, API gateway, or data layer. The "gatekeeper" that acts on PDP decisions.

Related:PDPExternalized Authorization

Permission

A specific action that can be performed on a resource. "Read customer record" or "Approve transaction" are permissions. Permissions are typically grouped into roles or policies.

Related:EntitlementRolePolicy

Policy

A rule or set of rules that determines access. Can be simple ("admins can access everything") or complex ("users can access customer records in their region during business hours").

Related:PBACPDPExternalized Authorization

Policy Engine

Software that evaluates policies against requests and returns decisions. The core of any authorization platform. Examples include OPA, Cedar, and various commercial engines.

Related:PDPOPAPolicy

Policy Sprawl

The proliferation of inconsistent access policies across different applications and systems. A symptom of decentralized authorization that makes governance and compliance difficult.

Related:Authorization DebtExternalized Authorization

R

RBAC

Role-Based Access Control. Access decisions based on roles assigned to users. Simple and widely used, but limited when you need finer-grained or context-aware decisions.

Related:ABACPBACRole

Real-Time Authorization

Making access decisions at the moment of access, with current context, rather than relying on pre-computed permissions. Essential for dynamic, context-aware security.

Related:Context-Aware AuthorizationPDPZero Trust

Rego

The policy language used by OPA (Open Policy Agent). A declarative language for expressing policies. Powerful and flexible, but requires developer expertise to author and maintain.

Related:OPAPolicyPolicy Engine

Role

A named collection of permissions assigned to users. "Admin," "Editor," "Viewer" are common roles. Role explosion occurs when organizations create too many roles to manage.

Related:RBACPermissionRole Explosion

Role Explosion

The uncontrolled growth of roles in an RBAC system, often to the point where roles become meaningless or unmanageable. A common symptom of trying to use roles for fine-grained access control.

Related:RBACRoleAuthorization Debt

Row-Level Security

Restricting access to specific rows in a database based on user context. "Users can only see customers in their region" is a row-level security policy.

Related:Fine-Grained AuthorizationData Access Control

S

SAML

Security Assertion Markup Language. An XML-based standard for exchanging authentication and authorization data between identity providers and service providers. Common in enterprise SSO.

Related:SSOIdPAuthentication

Separation of Duties

A control principle requiring multiple people to complete sensitive tasks. Authorization systems must enforce SoD policies—for example, preventing the same person from creating and approving a transaction.

Related:CompliancePolicyAccess Control

SSO

Single Sign-On. Authentication mechanism allowing users to log in once and access multiple applications. SSO solves identity, not authorization—knowing who someone is doesn't tell you what they can do.

Related:AuthenticationIdPSAML

Z

Zero Standing Privileges

An approach where users have no persistent access rights. All access is granted just-in-time based on need and automatically expires. The logical end-state of least privilege.

Related:Just-In-Time AccessLeast PrivilegeZero Trust

Zero Trust

A security model that requires verification for every access request, regardless of location or network. "Never trust, always verify." Authorization is a critical component—you can't verify without knowing what's allowed.

Related:Context-Aware AuthorizationLeast PrivilegeReal-Time Authorization

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