Federated identity, a revolutionary authentication approach, is transforming how we access and interact with online services. Gone are the days of managing multiple usernames and passwords for different applications and platforms. With federated identity, users can enjoy a seamless and secure authentication experience using a single set of credentials.

This article will explore the concept of federated identity and its significance in our digital lives. We will dive into the functionalities and benefits of federated identity, discussing how it simplifies the authentication process and enhances user convenience.

What is Federated Identity?

Federated identity, also known as federated identity management or federated authentication, is a system that enables individuals to use their digital identities across multiple organisations or systems without the need for separate login credentials for each entity. It allows users to authenticate once with an identity provider and then use that authentication to access various services or applications provided by different service providers.

Components of Federated Identity

Federated identity involves three main entities and components that enable seamless authentication and authorisation across multiple organisations or systems. These entities are Identity Providers (IdPs), Service Providers (SPs), and Users. Let’s delve into each entity and its components in detail:

Identity Providers (IdPs):

An Identity Provider is a trusted organisation or system that authenticates users and provides them with identity information. The IdP acts as the central authority for verifying the user’s identity. It typically consists of the following components:

a. Authentication Mechanisms: IdPs support various authentication methods to verify the user’s identity, such as passwords, biometrics (fingerprint or facial recognition), smart cards, or multi-factor authentication (combining two or more authentication factors).

b. User Identity Store: The IdP maintains a user identity store or directory that contains user information, such as usernames, email addresses, attributes, and authentication credentials. This information is used during the authentication process.

c. Identity Assertion: After successful user authentication, the IdP generates an assertion or token that contains the user’s identity information and attributes. The IdP digitally signs this assertion to ensure its integrity and authenticity.

d. Federation Metadata: IdPs publish federation metadata, which includes information about their authentication methods, supported protocols (e.g., SAML or OpenID Connect), public keys for signature verification, and endpoint URLs for authentication requests.

Service Providers (SPs):

Service Providers are organisations or systems that offer services or resources to users. They rely on the identity information the IdP provides to authorise user access to their services. The components of SPs include:

a. Service Offerings: SPs provide various services, applications, or resources that users want to access. These include web applications, cloud services, online banking platforms, e-commerce websites, and enterprise systems.

b. Service Configuration: SPs need to be configured to accept federated identities and trust specific IdPs. They maintain metadata about the IdPs they trust, including the IdP’s federation metadata and public keys for signature verification.

c. Attribute Mapping: SPs define how they consume and use the attributes the IdP provides. These attributes may include user roles, permissions, profile information, or any other relevant user data required for authorisation and personalisation within the SP’s services.

d. Single Sign-On (SSO): SPs implement SSO functionality, where users who have already authenticated with an IdP can seamlessly access multiple services without re-authenticating for each service.


Users are individuals who have identities within the federated identity system. They can access various services from different SPs using their authenticated identity from the IdP. The components related to users include:

a. User Authentication: Users initiate the authentication process by providing their credentials to the IdP. This can be a username/password combination, biometric data, or any other authentication method the IdP supports.

b. User Identity Assertion: After successful authentication, the user is issued an identity assertion or token by the IdP. This token contains information about the user’s identity and attributes, which is presented to the SP during authorisation.

c. Consent and Attribute Release: Users may be able to control which attributes are released to specific SPs. Depending on the user’s privacy preferences and the information required by the SP, the user may consent to share specific attributes with the SP.

d. Single Sign-On Experience: Users benefit from a single sign-on experience, where they only need to authenticate once with the IdP and then gain access to multiple services offered by different SPs without needing separate login credentials.

These three entities and their components form the foundation of federated identity systems. They work together to establish trust, authenticate users, exchange identity information, and enable seamless access to services across different organisations or systems.

How Does Federated Identity Work?

Federated Identity

Federated identity is a system that allows individuals to use their existing digital identities to access multiple systems or services across different organisations without the need for separate usernames and passwords. It works through a series of steps that involve trust relationships between entities involved in the authentication process.

The process begins with the user wanting to access a Service Provider (SP) service. The user initiates the authentication process instead of creating new login credentials for that specific service. The SP recognises the need for authentication but doesn’t have direct access to the user’s credentials. Therefore, the SP redirects the user to an Identity Provider (IdP) trusted to authenticate users.

At the IdP, the user goes through the authentication process. This typically involves providing a username and password or other authentication methods like multi-factor or biometrics. The IdP verifies the user’s identity based on the provided credentials.

Once the user is successfully authenticated, the IdP generates an identity assertion or token. This assertion contains information about the user’s identity and attributes, such as username, email address, or group memberships. To ensure the integrity and authenticity of the assertion, the IdP digitally signs it.

The user is then redirected back to the SP with the identity assertion. The SP receives the assertion and verifies its authenticity by validating the digital signature. This step confirms that a trusted IdP issued the assertion and has not been tampered with.

Next, the SP consumes the user’s identity assertion and extracts the relevant attributes needed for authorisation and personalisation within its services. These attributes could include user roles, permissions, profile information, or any other data the SP requires to provide personalised services.

The user is granted access to the requested service based on the extracted attributes and the SP’s access policies. The SP recognises the user as authenticated without needing separate login credentials. This enables a seamless user experience where the user can access multiple services offered by different SPs without the need to re-authenticate. This Single Sign-On (SSO) experience streamlines the user experience and eliminates the need to remember multiple usernames and passwords.

During the user’s session with the SP, the SP may periodically validate the user’s identity assertion with the IdP to ensure its ongoing validity. This helps maintain a secure and trusted session for the user while accessing the SP’s services.

Federated identity relies on standardised protocols such as SAML, OIDC, or OAuth to facilitate the secure exchange of identity information between the IdP and SP. These protocols define the message formats, authentication flows, and security mechanisms for a successful federated identity implementation.

By adopting federated identity, organisations can provide a seamless and secure user experience, reduce the burden of managing multiple user credentials, and enhance interoperability between different systems and applications. It promotes trust and collaboration among organisations while maintaining the privacy and security of user identities.

Technologies Used in Federated Identity

Federated identity relies on various technologies and protocols to facilitate secure and seamless authentication and authorisation across domains and organisations. Let’s explore some of the key technologies used in federated identity in more detail:

  1. Security Assertion Markup Language (SAML): SAML is an XML-based open standard for exchanging authentication and authorisation data between identity and service providers. It enables single sign-on (SSO) functionality by allowing the identity provider to issue security assertions containing user identity information to the service provider. SAML provides a secure and standardised way to authenticate users across different systems and domains.
  2.  OpenID Connect (OIDC): OIDC is an identity layer built on the OAuth 2.0 protocol. It provides a framework for authentication and access delegation, allowing users to log in to multiple websites or applications using their existing social media or email accounts. OIDC enables federated identity by allowing service providers to rely on identity providers to authenticate users and obtain user identity information in a standardised manner.
  3.  OAuth 2.0: OAuth 2.0 is an authorisation framework that allows users to grant limited access to resources from one platform to another without sharing their credentials. It is commonly used in federated identity scenarios to facilitate delegated authorisation. OAuth 2.0 enables users to grant permission to a service provider (relying party) to access their resources stored with an identity provider (resource owner) on their behalf.
Federated Identity

Examples of Federated Identity

Single Sign-On (SSO) with Google: Google offers federated identity services through its Google Accounts. With Google SSO, users can log in to various third-party applications and websites using their Google credentials. Users are redirected to Google’s authentication service When they try to access a service that supports Google SSO. The user then provides their Google username and password. Upon successful authentication, Google issues an identity token to the service provider. The service provider validates the token and grants the user access without requiring them to create a separate account.

Social Media Sign-In: Many websites and mobile apps allow users to sign in using their social media accounts, such as Facebook, Twitter, or LinkedIn. This form of federated identity is where the social media platform acts as the identity provider. When a user chooses to sign in with their social media account, the website or app redirects them to the respective social media platform for authentication. Once the user is authenticated, the social media platform provides an identity token to the service provider, enabling the user to access the services without needing separate credentials.

Government Identity Systems: Some countries have implemented federated identity solutions for citizens to access government services. For example, Estonia has an e-ID system called “Estonian ID card,” which serves as a federated identity solution. Citizens can use their ID cards to authenticate themselves to government services, such as tax filing, healthcare, and voting systems. The ID card contains a digital certificate verified by government service providers, allowing citizens to access services securely and conveniently.

Benefits of Federated Identity

  1. Enhanced Security: Federated identity enhances security by leveraging robust authentication and authorisation mechanisms. Identity providers and service providers can implement advanced security measures, such as multi-factor authentication, to ensure the authenticity of users. Additionally, federated identity systems employ secure protocols and encryption techniques to protect the transmission of identity information, reducing the risk of unauthorised access and identity theft.
  2.  Centralised Identity Management: Federated identity allows organisations to centralise identity management processes, reducing the administrative burden associated with user provisioning and de-provisioning. Instead of managing user accounts individually for each service or application, administrators can manage user identities in a central identity provider. This centralised approach simplifies user lifecycle management, making granting and revoking access privileges across various systems easier.
  3.  Collaboration and Interoperability: Federated identity enables secure collaboration and interoperability between organisations, platforms, and domains. It establishes trust relationships between identity providers and service providers, allowing users to access resources across organisational boundaries seamlessly. This promotes collaboration, data sharing, and business partnerships without the need for separate accounts or complex integration efforts.
  4.  Privacy and User Control: Federated identity systems often prioritise user privacy and give users control over their personal information. Users can choose which attributes or data to share with service providers, ensuring that sensitive information is not exposed unnecessarily. Federated identity frameworks often employ privacy-preserving technologies like tokenisation or pseudonymisation to protect user privacy while enabling secure service access.
  5.  Scalability and Cost Efficiency: Federated identity offers scalability and cost efficiency benefits for service providers and users. Organisations can leverage existing identity infrastructure and reuse identity providers, reducing the need for extensive user management systems. Users can access multiple services without creating and managing separate accounts for each, minimising account setup and maintenance efforts.

In summary, federated identity provides various benefits, including simplified user experience, single sign-on capability, enhanced security, centralised identity management, collaboration opportunities, privacy protection, and scalability. These advantages make federated identity an effective approach for achieving seamless and secure access to applications and services while improving user convenience and organisational efficiency.

Challenges and Best Practices

Federated identity brings many benefits to organisations, but it also comes with certain challenges that need to be addressed for successful implementation. Let’s explore some common challenges associated with federated identity and discuss best practices to overcome them:

  1. Trust and Security: Trust is a critical aspect of federated identity, as it involves relying on external identity providers. Organisations need to establish trust relationships with identity providers to ensure the security and integrity of user identity information. Best practices include a thorough evaluation and due diligence of identity providers, verifying their security practices, certifications, and compliance with industry standards. Regular security audits and monitoring can help ensure the ongoing security of the federated identity infrastructure.
  2.  Interoperability: Federated identity often involves integrating different systems, platforms, and technologies. Achieving interoperability can be challenging due to variations in protocols, token formats, and identity attribute mappings. Choosing standards-compliant technologies and protocols supporting interoperability, such as SAML, OIDC, and OAuth 2.0, is vital. Organisations should invest in tools and solutions that provide seamless integration and interoperability capabilities to simplify the deployment and management of federated identity.
  3.  User Experience: A seamless and user-friendly experience is crucial for successful federated identity implementation. Users should be able to log in once and access multiple applications without re-authenticating. Implementing single sign-on (SSO) functionality using SAML, OIDC, or similar protocols can enhance the user experience. To cater to diverse user needs, it is also essential to ensure that the federated identity solution supports various devices and platforms, including web, mobile, and desktop.
  4.  Identity Mapping and Attribute Exchange: Federated identity involves the exchange of user identity attributes between identity providers and service providers. Ensuring consistent attribute mappings and exchanging only necessary and appropriate attributes is essential for privacy and data protection. Organisations should establish clear guidelines and policies for attribute exchange, define the necessary attributes for each application or service, and implement attribute filtering mechanisms to control the information shared between parties.
  5.  Governance and Lifecycle Management: Federated identity requires effective governance and lifecycle management to handle user provisioning, de-provisioning, and role management across multiple systems. Organisations should establish clear processes and policies for managing user accounts, ensuring timely provisioning and de-provisioning access, and enforcing consistent identity lifecycle management practices. Automated identity lifecycle management tools can streamline these processes and help organisations maintain control and compliance.
  6.  Scalability and Performance: Federated identity systems must efficiently handle large volumes of authentication and authorisation requests. Organisations should design and deploy a scalable infrastructure to handle increased user loads and ensure optimal performance. Implementing caching mechanisms, load balancing, and optimising network infrastructure can help enhance the scalability and performance of the federated identity solution.
  7.  Compliance and Regulatory Requirements: Organisations must consider compliance and regulatory requirements when implementing federated identity. Depending on the industry and geographic location, specific data protection, privacy, and security regulations may be required. It is important to thoroughly assess applicable regulations and ensure that the federated identity solution is designed and configured to meet these requirements. Regular audits and compliance checks can help maintain compliance over time.
Federated Identity

To address these challenges and ensure the successful implementation of federated identity, organisations should follow these best practices:

  • Define a clear strategy and roadmap for federated identity implementation, considering the organisation’s specific requirements and objectives.
  •  Conduct thorough risk assessments and security evaluations of identity providers and technologies before establishing trust relationships.
  •  Establish strong governance and policies for attribute exchange, user provisioning, de-provisioning, and role management.
  •  Implement robust identity and access management (IAM) practices and solutions to centralise control and ensure consistency.
  •  Regularly monitor and audit the federated identity infrastructure for security, compliance, and performance.
  •  Stay updated with evolving standards, technologies, and best practices in federated identity to ensure ongoing security and effectiveness.
  •  Provide user education and awareness about federated identity’s benefits and proper usage to enhance adoption and mitigate user-related challenges.

By addressing these challenges and following best practices, organisations can successfully implement federated identity solutions that provide secure, seamless, and efficient access management across diverse systems and domains.

From streamlining user experiences to enhancing scalability and compliance, federated identity offers a powerful solution for organisations in today’s interconnected world. As technology evolves, federated identity will remain a key pillar of modern enterprise security strategies. So, keep exploring, stay vigilant, and embrace the power of federated identity to protect the digital landscape we all share.