What is Single Sign-On?

What is Single Sign-On?

Single Sign-On (SSO) is an authentication method that allows users to log in once and access multiple applications, systems, or services without needing to re-enter credentials for each one. Single Sign-On streamlines the user experience, improves security, and reduces the burden of managing multiple passwords. It is widely regarded as a cornerstone of modern Identity Access Management (IAM) because it enhances user experiences while supporting strong Zero Trust identity security practices.

How Single Sign-On Works

1. Centralized Authentication

When a user logs in through a Single Sign-On system, they authenticate with a central identity provider (IdP) like Microsoft Azure Active Directory and Google Workspace.

2. Session Token or Credential Exchange

Once the user is authenticated, the IdP generates a secure token (e.g., SAML, OAuth, OpenID Connect). This token is used to validate the user’s identity with various applications or systems.

3. User Access to Multiple Resources

As long as the session remains active, the user can access all integrated systems without needing to log in again.

Benefits of Single Sign-On

Convenience

Users only need to remember one set of credentials, reducing password fatigue. Single Sign-On also simplifies the login process for employees, contractors, customers, or partners.

Improved Security

Single Sign-On minimizes the need for password reuse and reduces the risk of password-related attacks (e.g., phishing, credential stuffing). Centralized authentication enables organizations to implement stronger security measures, such as multi-factor authentication (MFA).

Enhanced Productivity

Users don’t need to waste time repeatedly logging in to different systems or recovering forgotten passwords. This facilitates seamless transitions between applications.

Centralized Management

Administrators can manage user access, monitor activity, and enforce policies from a single point. This makes it easier to revoke access when employees leave or when their roles change.

Compliance

Single Sign-On supports audit and compliance requirements by providing a single source for identity management and activity logging.

Single Sign-On Protocols and Standards

Single Sign-On relies on various protocols to enable secure and efficient authentication:

SAML (Security Assertion Markup Language)

This is commonly used for enterprise applications. SAML provides authentication and authorization between the IdP and service providers.

OAuth 2.0

This is a framework for secure authorization, often used for API access. OAuth 2.0 enables users to grant limited access to resources without sharing their passwords.

OpenID Connect (OIDC)

Built on top of OAuth 2.0, OIDC provides authentication and identity verification. It is often used for web and mobile applications.

Kerberos

A network authentication protocol used in many enterprise systems. Kerberos relies on ticket-granting for secure, Single Sign-On experiences.

Challenges to Single Sign-On Implementation

Single Point of Failure

If the Single Sign-On system is compromised or experiences downtime, users may lose access to all connected applications. To mitigate this risk, organizations must use redundancy, backups, and robust identity security practices.

Complex Integration

Integrating legacy or non-standard systems with a Single Sign-On solution can be challenging. Organizations should consider choosing an Identity Governance and Administration (IGA) solution that has the capacity to adapt to an organization’s specific requirements.

Dependency on IdP

Organizations must ensure the identity provider is secure, reliable, and compliant with their needs.

Single Sign-On Use Cases

Corporate Environments

Employees, contractors, partners, and vendors can access multiple tools like email, project management platforms, HR systems, and file storage with one login.

Customer Portals

Users can access various services (e.g., billing, support, account management) with a single set of credentials.

Educational Institutions

Students and staff use Single Sign-On to access learning management systems, library resources, and administrative tools.

Where to Learn More

While Single Sign-On helps grant trust to users and applications, no one access control method can mitigate all security risks. A modern Identity Governance and Administration (IGA) solution provides organizations with a layered approach to identity security.

A modern IGA solution like Omada Identity Cloud brings a level of visibility into an organization that helps strengthen SSO security controls. In addition, the visibility that IGA provides into key data points like who is accessing what and how often, from what IP ranges are they accessing data and applications, group members and their respective activity within those groups, peer analysis, and more, can help organizations improve their ability to meet compliance, and make intelligent decisions about who should have access to what.

Omada helps customers implement foundational elements within 12 weeks to enable customers to improve security, enhance productivity, and meet compliance.