What Is an Attribute Statement?

Updated on October 24, 2025

An Attribute Statement is a critical component of Security Assertion Markup Language (SAML) assertions that carries user-specific data between identity systems. This XML element contains a collection of attributes—or “claims”—about an authenticated user, enabling applications to make informed authorization decisions without maintaining their own user databases.

Unlike an Authentication Statement, which verifies how and when a user logged in, an Attribute Statement provides the specific user data that applications need to grant access to resources. This distinction is fundamental to understanding federated identity systems.

When a user accesses a federated application, the Identity Provider (IdP) issues a SAML assertion containing both authentication proof and user attributes. The Attribute Statement portion of this assertion carries information such as email addresses, group memberships, roles, and other user properties that the Relying Party (RP) needs for authorization decisions.

Definition and Core Concepts

An Attribute Statement is a component of a SAML assertion that contains a collection of attributes about the user who has been authenticated. It represents a fundamental part of the claims-based identity model, where the relying party trusts the IdP to verify a user’s identity and provide the necessary information for authorization.

The foundational concepts include:

• SAML Assertion: An XML document that contains claims about a subject. An assertion is issued by an IdP and consumed by an RP.
• Identity Provider (IdP): The service that authenticates the user and issues the security token.
• Relying Party (RP): The application or service that trusts the IdP and uses the security token to grant access.
• Claims: The specific assertions about the user contained within the security token.
• Authorization: The process of determining what a user is permitted to do once their identity has been authenticated.

Each attribute within the statement consists of an attribute name and one or more attribute values. The IdP determines which attributes to include based on its configuration and the user’s profile in the underlying user store.

How It Works

An Attribute Statement is generated by the Identity Provider after a user has been successfully authenticated. The process follows a specific sequence of steps that ensures secure transmission of user attributes.

• User Authentication: A user logs in to an application (the RP), which redirects them to the IdP for authentication.
• IdP Authentication: The user enters their credentials, and the IdP validates them against its user store.
• Statement Generation: Upon successful authentication, the IdP generates a SAML assertion. It consults its user store (such as Active Directory) to retrieve the user’s attributes.
• Attribute Creation: The IdP creates an Attribute Statement that contains these attributes. Each attribute is represented by an <Attribute> element, which has a name (such as emailAddress) and one or more values (such as [email protected]).
• Assertion Transmission: The IdP sends the entire SAML assertion, which includes the Authentication Statement and the Attribute Statement, back to the RP.
• Validation and Access Grant: The RP receives the assertion, validates its signature, and then uses the claims in the Attribute Statement to make authorization decisions. For example, if the user’s role attribute is “administrator,” the RP can grant them access to a management console.

The entire process relies on pre-established trust relationships between the IdP and RP, typically configured through metadata exchange and certificate validation.

Key Features and Components

• Dynamic Content: The attributes in an Attribute Statement are dynamic and are based on the user’s profile in the Identity Provider’s user store. Attributes can change based on user role modifications, group membership updates, or profile changes.
• Fine-Grained Authorization: Attribute statements enable the RP to make granular authorization decisions without having to query a separate user database. This reduces latency and simplifies the application architecture.
• Interoperability: Because the Attribute Statement is part of the standardized SAML specification, it ensures that different IdP and RP products can securely interoperate across vendors and platforms.
• Security and Trust: The entire process is built on the cryptographic trust established between the IdP and the RP, which ensures the integrity of the claims. Digital signatures protect against tampering and verify the assertion’s authenticity.

The XML structure of an Attribute Statement includes specific elements that define the attribute name, name format, and values. Multiple values can be associated with a single attribute, allowing for complex authorization scenarios.

Use Cases and Applications

Attribute statements are central to modern identity federation scenarios across various organizational contexts.

• Role-Based Access Control (RBAC): An RP can use a role attribute in the Attribute Statement to determine a user’s access level. For example, a user with a “manager” role attribute might receive access to supervisory functions, while a “employee” role provides standard access.
• User Profile Provisioning: The RP can use the attributes in the statement (such as first name, last name, email) to create a new user profile in its local database. This eliminates manual user provisioning and ensures data consistency across systems.
• Centralized Authorization: The IdP can be configured to add attributes to the statement based on the user’s group memberships in Active Directory, allowing the RP to centralize its authorization logic. Group memberships can drive access to specific applications, features, or data sets.
• Multi-Tenant Applications: Software-as-a-Service (SaaS) applications use organization or tenant attributes to isolate user access to appropriate data and functionality within shared application instances.
• Compliance and Audit: Attribute statements can carry compliance-related attributes such as security clearance levels, training certifications, or audit trail information required for regulatory compliance.

Advantages and Trade-offs

Advantages: Simplifies authorization logic for the RP, as it does not need to manage user data itself. It provides a secure, standardized way to transfer user information between trusted systems. The approach reduces administrative overhead by centralizing user attribute management at the IdP level.

Trade-offs: Can introduce a new attack vector if the assertion or the underlying trust relationship is not configured correctly. The RP must be configured to correctly interpret the attribute names and values, requiring careful coordination between IdP and RP administrators.

Configuration complexity increases as the number of attributes and relying parties grows. Attribute mapping between IdP user stores and RP expectations requires ongoing maintenance. Network dependencies mean that RP authorization decisions depend on the availability and performance of the IdP.

Privacy considerations arise when sensitive user attributes are transmitted between systems, requiring careful evaluation of which attributes are necessary for each RP.

Key Terms Appendix

• SAML (Security Assertion Markup Language): An XML-based standard for exchanging authentication and authorization data between identity providers and service providers.
• SAML Assertion: An XML document containing claims about a user, digitally signed by the issuing IdP.
• Identity Provider (IdP): The service that authenticates users and issues SAML assertions containing user attributes.
• Relying Party (RP): The application that trusts the IdP and uses SAML assertions to make access control decisions.
• Claims: Assertions about a user’s identity, attributes, or capabilities contained within a security token.