Compare Azure AD Authentication Mechanisms
Single Sign-On (SSO)
Single Sign-On (SSO) lets users access multiple applications by signing in just once with a single set of credentials. This removes the need for users to remember and manage multiple passwords, and it reduces the administrative work of managing user access across different applications. SSO works especially well with SaaS applications like Microsoft 365 and Salesforce, where it creates a seamless integration and boosts user productivity.
Multifactor Authentication (MFA)
Multifactor Authentication (MFA) adds an extra layer of security by requiring users to verify their identity using more than one method. Typically, this involves something the user knows (a password) and something they have (a mobile device). Azure MFA supports several verification methods, including SMS text messages, phone calls, and notifications through a mobile app.
Managed Identities and Service Principals
Managed Identities are identities that Azure manages automatically. They allow a resource to authenticate to any service that supports Azure AD authentication without needing to manage any credentials. There are two types:
- System-assigned managed identities are tied directly to a specific Azure resource, such as a virtual machine or a function app. When the resource is deleted, the identity is deleted too.
- User-assigned managed identities are standalone resources that you can assign to one or more Azure resources. They exist independently of any single resource and can be reused.
Service Principals are used by applications, services, and automation tools to access Azure resources securely. They function similarly to managed identities but require you to explicitly manage their credentials, such as certificates or client secrets.
OAuth 2.0 and OpenID Connect
Azure AD supports OAuth 2.0 and OpenID Connect, which are modern authentication protocols. OAuth 2.0 provides secure access delegation, allowing a third-party application to access resources on behalf of a user without sharing the user's password. OpenID Connect builds on OAuth 2.0 to provide identity information, verifying who the user is. These protocols enable secure access for third-party applications while keeping the user's credentials private.
Federation Services
For organizations with complex hybrid environments that span on-premises and cloud resources, integrating federation services such as Active Directory Federation Services (AD FS) can provide seamless identity management. Federation allows users to sign in to cloud applications using their existing on-premises Active Directory credentials. This creates a consistent authentication experience while maintaining security and compliance, because the organization retains control over authentication policies on-premises.
Conditional Access
Conditional Access policies enhance security by controlling how and when users can access applications based on conditions like user location, device health, or sign-in risk. For example, you can enforce MFA only when a user signs in from an untrusted location or uses a device that does not meet compliance standards. This ensures that only compliant and secured access is granted, balancing security with user convenience.