5.1.2 Privacy

The privacy considerations in [MS-MWBF] section 5.1.5 apply to the extensions in this document. The extensions also introduce new privacy concerns.

The Query String Response Transfer Protocol is used to communicate security tokens from one party to another by using the query string of the HTTP request URL. The use of Secure Sockets Layer/Transport Layer Security (SSL/TLS) prevents the exposure of user information outside the services participating in the protocol (see [MS-MWBF] section 5.1.3); however, a GET message might provide a lesser degree of confidentiality than a POST message due to URL tracking concerns. For example, web browser requestor implementations might track URL history, or web proxy servers might log URLs.

The SAML 1.1 Assertion Extension provides a method for including SIDs in a SAML assertion. These SIDs might identify user identity, capabilities, or affiliations. For this reason, SIDs should not be included indiscriminately; rather, their distribution should be limited to specific relying parties.<24>