SSO has become essential for modern applications. It lets you offer a secure, seamless login experience to your customers or users, reducing friction and letting them get to your application or applications quickly.
For developers, SSO isn't just about reducing friction—it also lets you outsource management of identity so you don’t have to worry about it.
What is SSO?
SSO, or single sign-on, is an authentication method that allows users to access one or more applications with a single set of credentials, eliminating the need for them to remember and enter different passwords or repeatedly offer up other credentials. SSO creates a better user experience while enhancing security through centralized management of user identities and credentials.
SSO works by establishing a trust relationship between applications and an identity provider, which handles the verification of user credentials. The identity provider then issues tokens or other forms of identity proof which can be used by the trusting application.
With centralized authentication, often implemented using a customer identity and access management (CIAM) system, organizations gain improved access insight, control via policies, better management of permissions across applications, and enhanced security through consistent enforcement of authentication standards such as use of multi-factor authentication (MFA).
For developers implementing customer-facing applications, SSO reduces friction in the user journey, leading to higher conversion rates and improved customer satisfaction.
Benefits of SSO
SSO delivers significant benefits for both users logging in and organizations, by creating a frictionless authentication experience and enhancing overall security. By allowing users to access multiple applications with a single set of credentials, SSO eliminates password fatigue and reduces login frequency, streamlining the customer journey and improving conversion rates.
From a security perspective, centralized authentication enables consistent enforcement of password policies or breached password detection, simplified credential management, and faster implementation of security measures like MFA across all trusting applications. This centralization makes it easier to introduce advanced authentication features including:
- adaptive authentication
- risk-based access controls
- passwordless features such as magic links or passkeys
All of this without disrupting the user experience or requiring separate implementations for each application.
Additionally, SSO aids compliance efforts by providing audit trails and access controls that simplify reporting for regulations like GDPR, CCPA, and HIPAA. With all user logins flowing through a single system, organizations gain visibility into user access patterns. They can more easily demonstrate adherence to regulations with centralized logging and monitoring.
This consolidated approach to identity management reduces the burden on engineering teams, allowing them to focus on core application functionality rather than building and maintaining multiple authentication systems.
Challenges of SSO
It’s not all roses, though.
SSO introduces additional complexity to your application ecosystem, as it creates dependencies between the trusting applications and the identity provider. This interdependence means that changes to authentication flows, token formats, or security policies in the SSO solution can potentially impact multiple downstream applications. Developers must carefully consider how these systems interact and establish robust testing to ensure that updates don't disrupt users ability to log in. Additionally, SSO needs standard authentication protocols across applications; depending on the applications, this can require changes to existing codebases.
A significant concern with centralized authentication is the creation of a single point of failure (SPOF). If your SSO service or provider experiences downtime, customers may be unable to access any applications, affecting critical business operations. To avoid this, invest in high-availability solutions and disaster recovery plans to mitigate outage risks. Evaluate SSO provider's reliability guarantees and consider the business impact of authentication system failures when selecting a solution.
Implementation costs for SSO can be substantial, beyond licensing fees of the CIAM solution. These costs include:
- development time for integration
- staff training on the new systems
- ongoing maintenance after implementation
- planning and engineering time for user profile migration, if applicable
The initial implementation typically requires specialized knowledge of identity protocols like Security Assertion Markup Language (SAML), OAuth, and OpenID Connect (OIDC), which may mean hiring experts.
Compatibility challenges often arise when integrating SSO with legacy applications or third-party systems that weren't designed with modern authentication protocols in mind. Applications may lack support for standards like SAML or OAuth, requiring middleware solutions to enable SSO functionality.
Migration from existing authentication systems may present additional hurdles. These include:
- maintaining existing user credentials
- managing the transition period when both systems might need to operate in parallel
- ensuring that user profile data and permissions are correctly mapped between systems
Develop a comprehensive migration strategy that addresses any potential data inconsistencies and plan for time to handle integration issues. Migrations almost always take longer than you think.
Single Sign-On And Federation
Federation and SSO are related but distinct identity management concepts. They serve different purposes. While SSO enables users to access multiple applications with one set of credentials, federation extends this capability across organizational boundaries by establishing trust relationships between separately managed identity stores.
The key distinction is that federation involves explicitly trusting external identity stores outside your organization's direct control, allowing users to authenticate using credentials managed by others. These include social media platforms like Google or Facebook or third-party identity providers like a customer’s Entra ID or Okta instance. Cross-organizational authentication enables seamless collaboration without requiring additional user accounts. As a bonus, it delegates control and responsibility for the identity to the external provider.
In contrast, SSO typically operates within a single organization's ecosystem, leveraging either internal identity sources (like a corporate directory) or external providers that the organization has selected.
SSO focuses primarily on streamlining the user experience and centralizing authentication management. Federation addresses the broader challenge of sharing identity across organizational boundaries, enabling businesses to safely collaborate with partners, contractors, and customers without managing their identity lifecycle.
SSO Implementation Steps
1. Choose an Authentication Protocol
Select the appropriate protocol based on your technical and ecosystem compatibility requirements:
- OIDC: a modern protocol built on OAuth 2.0, ideal for web and mobile applications; this is the recommended option
- SAML: an enterprise-focused protocol with robust, sometimes complex, security features, commonly used for B2B or older older applications
Why It Matters: Your protocol choice affects integration complexity, security features, and compatibility with your application stack. You might notice that “build your own” is not on this list; it’s not recommended.
2. Define Participating Parties
Here are the components needed for an SSO implementation:
- OpenID Provider: the system that authenticates users and issues proof of user identity and authentication
- Relying Parties: the applications that will accept the proof of authentication
- Users: the individuals who will log in through the system
- Clients: mobile or web applications used to interact with the other components
SSO systems definitely use a lot of jargon. Below is a table mapping terms between OIDC (the terminology used above and throughout this article) and SAML, the older, enterprise-y technology.
Why It Matters: Understanding the relationships between your applications, store of identity and users helps planning, establishing trust, and understanding user and data flows.
3. Establish Trust Relationships
Configure trust between your OP, which manages user identity, and RPs, the applications which trust the OP:
- Exchange metadata or configuration information between systems.
- Set up public/private keypairs for secure signing of tokens.
- Share or publish the public portions of the keypairs.
- Configure allowed callback URLs and validation parameters.
- Define token lifetimes and security constraints.
Why It Matters: Establishing trust makes sure only the known and trusted OP can issue identity tokens for the RPs.
4. Implement Mapping
Define how user claims will be used across applications:
- Identify required claims for each RP (the trusting applications).
- Make sure the OP has all the required information, or figure out a way to get it.
- Configure what information is shared with which RPs.
- Set up any needed transformations of claims.
- Address privacy considerations for sensitive data. Do you need to scrub it, encrypt it or can you simply remove it?
Why It Matters: Proper mapping ensures applications receive the user profile data they need while respecting user privacy and regulations.
5. Integrate Applications with SSO
Modify your applications to accept identity assertions from the OP:
- Choose protocol-specific libraries or SDKs; this will differ based on the protocol you picked above.
- Update applications to send users to the OP when they authenticate.
- Configure applications to validate tokens.
- Implement session management, including session termination if needed.
Why It Matters: Application integration is often the most time-consuming part of SSO implementation and requires careful manual and automated testing.
6. Implement Logout Functionality
Design and implement support for logging users out.
- Decide between front-channel (on the client) and back-channel (on the server) logout mechanisms.
- Plan and configure active session termination across applications where needed.
- Implement proper redirects after logout.
- Consider session timeouts and inactivity handling, in particular how session length on the OP differs from session length at each of the RPs.
Why It Matters: Without proper logout, unintended application sessions can remain alive, creating confusion and possibly security vulnerabilities.
7. Develop Testing Strategy
Create a testing plan that validates authentication flows:
- Test successful authentication paths across all applications
- Verify error handling for invalid credentials or tokens
- Test session timeouts and renewal processes
- Validate logout functionality
- Test across different browsers, devices, and network conditions
- Simulate high traffic and failure scenarios
Create automated tests for high-risk, important, or unstable user flows so that you can know if they change or break.
You should also plan to set up different environments for your SSO server (dev, test, prod), the same as you have for your applications that depend on it. This way you can migrate changes or versions based on SDLC best practices.
Why It Matters: Thorough testing prevents issues in production that could block users from accessing applications.
8. Plan for Monitoring and Maintenance
Establish ongoing operational procedures:
- Implement logging and monitoring for authentication events as required by your compliance needs, including sending logs to SIEM tools or other log management solutions.
- Set up alerts for unusual activity or authentication failures, as well as a plan for how to handle them.
- Create a secret or certificate rotation schedule and the automated tooling or configuration do implement it.
- Develop a change management process for updates to the SSO configuration, preferring infrastructure as code to minimize configuration drift.
Why It Matters: SSO systems require ongoing maintenance to remain secure and functional.
Additional SSO Implementation Considerations
Starting A Login
Determine how and where users begin their authentication journey, as this impacts the user experience, security, and technical implementation. In particular, considerations for SSO built using SAML include:
- IdP-Initiated Flows: Users start at the identity provider and select which application to access after authentication.
- SP-Initiated Flows: Users start at the service provider (application), which redirects to the IdP for authentication; this is the recommended option because it is more secure.
OIDC is more straightforward and usually begins with creating a correct authorization URL pointing to the OP.
Why It Matters: The initiation point affects user journeys, security, and bookmarking.
Deep Linking
Often a user will log in after interacting with an application. For example, a user might browse to a page of an ecommerce site and then want to log in to purchase or save the item.
Make sure you support deep linking, which enables users to access specific application states after authentication, rather than the default landing page.
Why It Matters: Deep linking support minimizes the disruption of the user experience after logging in.
User Provisioning Strategies
You can’t SSO without a user account. Select appropriate user provisioning methods based on your requirements:
- Self-service Registration: Allow users to create accounts in applications by providing profile information and credentials; if allowed consider some kind of verification.
- Just-in-Time (JIT) Provisioning: Create user accounts in applications automatically during first login; the application trusts the OP.
- SCIM (System for Cross-domain Identity Management): Use this standardized API-based provisioning to provision users from an external identity store.
Why It Matters: Effective provisioning strategies make sure users have appropriate access across applications without human effort.
Account Linking and Identity Federation
Establish a strategy for managing users with multiple identities across different systems.
This is more important if you are using federation rather than pure SSO.
- Account Linking: connect separate user accounts based on verified claims like email or phone number
- Identity Mapping: maintain relationships, including immutable identifiers, between different identity providers for the same user
- Conflict Resolution: define procedures for handling duplicate or conflicting user information; this may be manual
Why It Matters: Customers, if offered multiple identity stores, may log in using different ones at different times. They may not remember which one they used. Work to provide a consistent experience.
Step-Up Authentication
When something is doing a risky action, simply being authenticated may not be enough. You can implement contextual security measures that adapt to risk levels and resource sensitivity:
- Risk-Based Authentication: adjust login requirements based on user behavior, location, or device
- Progressive Authentication: start with minimal friction and increase security by requiring additional credentials or actions for sensitive operations
- Authentication Level Mapping: define which resources require which levels of authentication assurance
Why It Matters: Step-up authentication balances security and user experience by applying appropriate protection levels. This might be useful when a financial application allows general account access with a password but requires biometric verification before initiating transfers above a certain threshold or to a new recipient.
Account Recovery and Self-Service
Design robust account recovery flows that maintain security while preventing as many instances of user lockout as possible:
- Multi-Channel Verification: use multiple communication channels or authentication methods to verify user identity during recovery
- Recovery Token Lifecycle: minimize timeframes and usage limits for recovery credentials
- Self-Service Options: provide user-friendly tools for password resets and account unlocking while balancing this operation with security
- Delegated Recovery: allow trusted administrators to assist with account recovery; providing a phone number is nice
Why It Matters: Without secure recovery options, users may be permanently locked out of their accounts or vulnerable to account takeover attacks
Ready to take control of SSO, user identity and access management?
Get started with FusionAuth for free today and experience the power of a developer-focused CIAM solution. With a comprehensive API, customizable workflows, and robust security features, FusionAuth gives you the flexibility and control you need to build secure and engaging user experiences.
Customer Identity and Access Management (CIAM) solutions have become essential for modern applications, enabling secure and seamless user interactions. For developers, CIAM isn't just about protecting data—it’s a way to streamline user management, improve customer experience, and meet complex compliance requirements without unnecessary effort.
What is the Difference Between CIAM and IAM?
While CIAM and IAM both handle user access, they serve different purposes. IAM focuses on managing internal users (employees or contractors), ensuring they have the appropriate level of access to company resources. CIAM manages external users (customers), emphasizing the user experience, security, and scalability. CIAM systems must be able to handle larger numbers of users. They often include features such as self-service account management and social login options for ease of use.
Table of Contents
What Challenges Do CIAM Solutions Solve?
CIAM products tackle a wide range of challenges faced by businesses and developers, including:
1. Securing Applications
CIAM systems address threats like credential stuffing, phishing, and account takeovers by implementing features like Multi-Factor Authentication (MFA), fraud prevention, and adaptive authentication.
2. Supporting Admin User Management
CIAM solutions streamline admin user management by providing tools for tasks like user account recovery and privilege management.
3. Scaling with Growth
The best CIAM solutions are designed to scale large user bases without introducing performance issues, making them ideal for applications with fluctuating or growing demand.
4. Simplifying Compliance
CIAM solutions offer tools for secure data handling, consent tracking, and auditing, making it easier to adhere to regulations like GDPR, CCPA, and HIPAA.
5. Improving User Experience
Tools like Single Sign-On (SSO), passwordless login, and simplified account recovery options minimize barriers to users logging in. CIAM systems may also provide self-service account management solutions, allowing users to manage their profile info, including credentials, without contacting customer support.
6. Streamlining Integration
CIAM platforms that are built with developers in mind provide APIs and SDKs that simplify the process of integrating authentication features into applications.
7. Managing Downstream Data
CIAM solutions facilitate data sharing via search or webhooks, ensuring businesses can efficiently access data to support broader application functionality or integration needs.
8. Optimizing Onboarding
By enabling social logins, progressive registration, multiple identity providers, and customizable registration forms, CIAM tools make it easy for users to sign up, increasing conversion rates.
9. Reducing Development Costs
CIAM solutions provide ready-to-use features that save developers from building custom authentication systems, allowing teams to focus on core application functionality.
Types of CIAM Solutions
CIAM solutions can be categorized by deployment model, focus area, and functional capabilities.
By Deployment Model
Cloud-Based CIAM Solutions
These are fully managed services hosted in the cloud, requiring minimal setup and maintenance from the organization. They are quick to deploy and easily scalable to handle fluctuating user volumes.
Best For: Organizations seeking a low-maintenance option that can adapt to rapid growth.
Examples: Auth0, Firebase, Frontegg, OneLogin, Cognito, Azure AD B2C.
On-Premises CIAM Solutions
Deployed on the organization's own infrastructure, these solutions offer full control over data and system management. This provides greater control over sensitive customer data and allows organizations to meet specific compliance or security requirements. It also allows engineering organizations to determine upgrade cycles that meet their needs.
Best For: Highly regulated industries or those with strict data sovereignty needs.
Examples: Keycloak, Gluu, FusionAuth, Duende IdentityServer.
Hybrid CIAM Solutions (Supports Cloud and On-Premises)
Combining the strengths of cloud and on-premises systems, hybrid solutions allow companies to choose where to host specific environments or sensitive data. This approach offers flexibility in workload management. As business needs change, you can move data from the cloud to on-premises or vice versa.
Best For: Businesses with mixed infrastructure requirements.
Examples: FusionAuth, Ping Identity.
By Focus Area
Developer-Centric CIAM Solutions
Designed for developers, these platforms offer extensive APIs, SDKs, and customizable workflows. This provides high flexibility and adaptability for unique use cases and allows for easy integration with custom-built applications.
Best For: Organizations with dedicated development teams who require fine-grained control over their CIAM implementation.
Examples: FusionAuth, Auth0.
Enterprise-Focused CIAM Solutions
These solutions prioritize robust security, integration with enterprise tools, and scalability for large organizations. They offer comprehensive lifecycle management features and built-in compliance support for complex regulatory requirements.
Best For: Large businesses with diverse user bases and stringent compliance needs.
Examples: Ping Identity, Microsoft Azure AD B2C.
Identity-First CIAM Solutions
With a strong emphasis on securing customer data, these solutions provide advanced authentication features, including fraud detection and risk-based authentication.
Best For: They are ideal for applications where data security is the primary concern, such as in finance, healthcare, and e-commerce.
Examples: Ping Identity.
Experience-Centric CIAM Solutions
These solutions prioritize user experience by offering seamless registration, authentication, and account recovery processes. This leads to enhanced customer satisfaction and retention. They also provide customizable user journeys to match brand identity.
Best For: Consumer-facing businesses focused on usability.
Examples: Auth0, FusionAuth.
9 Key Features to Look for in a CIAM Solution
1. Flexible Authentication Methods
Your chosen CIAM platform should support a variety of login options, including magic links, passkeys, username/password, and federated identity providers (e.g., Google, Facebook, SAML).
- Why It Matters: Users can choose their preferred authentication method, improving accessibility and reducing login friction.
- Example: A customer logs in using their Google account on a retail website without needing a separate password.
2. User Provisioning and Registration
You should be able to manage user provisioning through APIs, SCIM (System for Cross-domain Identity Management), or self-service registration portals.
- Why It Matters: Automates user onboarding and management, ensuring consistent and efficient identity provisioning across systems.
- Example: A new user signs up via a self-service portal and is able to access the application afterwards without any friction..
3. Self-Service Profile Management
Your CIAM platform should offer self-service profile management for users to update personal details, reset passwords, and manage preferences without administrator intervention.
- Why It Matters: Enhances user autonomy while reducing administrative workload.
- Example: A customer updates their contact information and notification preferences directly from their profile dashboard.
4. Multi-Factor Authentication (MFA) and Associated Security Features
Security features in your CIAM solution like MFA and risk-based authentication add multiple layers of protection against unauthorized access.
- Why It Matters: Strengthens account security and reduces risks associated with credential theft or phishing attacks.
- Example: A user further verifies their identity with a one-time code sent to their mobile device after entering their password.
5. Administrative User Management
Your admins should be able to oversee user accounts, manage roles and permissions, and enforce security policies through admin consoles.
- Why It Matters: Centralizes control over user access and security policies, simplifying management tasks.
- Example: An admin revokes access to a former employee’s account from a centralized dashboard.
6. Integration Points for Data Export
Your chosen CIAM platform should provide integration capabilities to extract user data for analytics, compliance, and third-party applications.
- Why It Matters: Ensures seamless data flow across systems, enabling actionable insights and reporting.
- Example: User login success and failure records are exported to an analytics platform for behavioral analysis.
7. Session Management
Your CIAM solution should offer controls for session timeouts, persistent logins, and automatic sign-offs to ensure secure and efficient user sessions.
- Why It Matters: Prevents unauthorized access from abandoned or shared devices while maintaining smooth user experiences.
- Example: A banking app automatically logs out inactive users after 10 minutes.
8. Customizable Flows and User Interface
Your CIAM solution should support custom login, registration, authentication workflows, and the look and feel of user-facing interfaces.
- Why It Matters: Aligns user experience with brand identity and adapts to specific business requirements.
- Example: A subscription service designs a branded login page with customized password recovery steps.
9. High Availability and Reliability
Your CIAM solution should ensure consistent uptime and scalability to handle large user volumes during peak traffic.
- Why It Matters: Guarantees uninterrupted service, even during traffic surges or system failures.
- Example: An e-commerce website handles a sudden spike in logins during a flash sale without disruptions.
Developer's Checklist for Evaluating CIAM Solutions
1. Single Sign-On (SSO)
- [ ] Does the CIAM solution support standards-based SSO protocols (e.g., SAML, OpenID Connect)?
- [ ] Can I easily integrate SSO with my existing applications and identity providers?
- [ ] Does the solution provide customization options for the SSO login experience (e.g., branding, user interface)?
- [ ] How does the solution handle SSO across different domains and subdomains?
2. Multi-Factor Authentication (MFA)
- [ ] Does the CIAM solution offer a range of MFA methods that my customers expect (e.g., push notifications, TOTP, biometrics, security keys)?
- [ ] Can I configure MFA policies based on user roles, risk profiles, or specific applications?
- [ ] How does the solution handle MFA recovery in case of lost devices or forgotten credentials?
3. Adaptive Authentication and Fraud Detection
- [ ] Does the CIAM solution offer risk-based authentication that adapts to user behavior and context?
- [ ] What factors does the solution consider for risk assessment (e.g., IP address, device fingerprint, geolocation, login history)?
- [ ] Can I configure risk thresholds and responses (e.g., step-up authentication, account lockout)?
- [ ] Does the solution provide real-time fraud detection capabilities (e.g., anomaly detection, machine learning)?
4. API-First Architecture for Easy Integration
- [ ] Does the CIAM solution have a well-documented and comprehensive API?
- [ ] Are there SDKs or examples available for my preferred programming languages and frameworks?
- [ ] Can I use the API to manage all aspects of identity and access (e.g., user registration, authentication, authorization)?
- [ ] How does the solution handle API versioning and backward compatibility?
5. Customizable User Journeys and Interfaces
- [ ] Can I customize the user registration, login, and account recovery flows?
- [ ] Does the solution offer pre-built templates or allow for complete customization of user interfaces?
- [ ] Can I integrate the CIAM solution with my existing branding and design guidelines?
- [ ] Does the solution support localization and internationalization for different languages and regions?
Bonus Considerations:
- [ ] Can the CIAM solution handle my current and future user base and transaction volume?
- [ ] Does the solution meet relevant security standards and comply with data privacy regulations (e.g., GDPR, CCPA)?
- [ ] Does the CIAM vendor have a strong track record and provide adequate support and documentation?
- [ ] Does the pricing model align with my budget and usage requirements (and is the pricing model straightforward)?
- [ ] Is the solution highly available (if using a cloud-based solution)?
Ready to take control of your user identity and access management?
Download FusionAuth for free today and experience the power of a developer-focused CIAM solution. With a comprehensive API, customizable workflows, and robust security features, FusionAuth gives you the flexibility and control you need to build secure and engaging user experiences.
