Which of the following authentication protocols allows organizations to trust each other's identity information?

WS-Federation is an authentication protocol that enables cross-organization collaboration by allowing different organizations to trust each other's identity information. It provides a mechanism for federating identities across organizational boundaries, facilitating single sign-on (SSO) experiences, and allowing secure sharing of identity assertions between trusted parties. This is particularly useful in enterprise environments where multiple identity providers need to interact seamlessly.

The protocol accomplishes this by allowing one organization to delegate authentication to another, effectively trusting the identity information that the other organization provides. This capability is key in environments where users move between disparate services or systems that may belong to separate organizations.

In contrast, OAuth and OpenID Connect are primarily focused on delegated authorization and establishing trust for obtaining access tokens or identity claims from a single source rather than building a federation of trust across multiple entities. LDAP is a protocol for accessing and maintaining directory services, but it does not inherently establish trust relationships between different organizations. Thus, while these other options serve critical roles in identity and access management, they do not facilitate the same level of mutual trust that WS-Federation does.