WS-Trust

WS-Trust is a specification that is part of the WS-Security framework, which establishes a standard for managing, issuing, and validating security tokens. Developed as an extension of WS-Security, WS-Trust provides additional protocols for secure message exchanges in web services and [[Service-Oriented Architecture (SOA)|SOA (Service-Oriented Architecture)]] environments.

WS-Trust defines how security tokens can be issued, renewed, and validated. This includes exchanging and brokering tokens between different trust domains. It enhances the security of [[SOAP]] (Simple Object Access Protocol) messages by enabling the integration of various security token models, like [[SAML (Security Assertion Markup Language)]], with web services.

WS-Trust supports federated identity scenarios where user credentials and identity information need to be securely shared across different security domains or services. It accommodates various types of security tokens, enabling flexibility in authentication and authorization mechanisms. The protocol defines a standard way for web services to establish and negotiate trust relationships, simplifying secure communications in distributed environments.

In [[Single Sign-On (SSO)|SSO]] systems, WS-Trust can be used to manage and validate the tokens that represent users' authenticated sessions, allowing them to access multiple services with a single set of credentials. It is used in securing web services by providing mechanisms for issuing and validating tokens that assert the identity and permissions of message senders. In enterprise applications, WS-Trust is used to manage security tokens for internal and external communications, ensuring that only authorized entities can access services.

A user wants to access a web service in a different organization, but the services require different types of security credentials. The user's home organization uses WS-Trust to issue a SAML token that the target web service can validate. This token encapsulates the user's identity and access rights, which the web service verifies to grant access. This process is integral to cross-domain federated access, enabling the user to securely access external services.