During an IdP initiated sign-on, what is NOT required to confirm a SAML assertion?

In an IdP (Identity Provider) initiated sign-on process using SAML (Security Assertion Markup Language), confirming a SAML assertion primarily involves verifying its authenticity and integrity, which requires two key components: the signatures associated with the assertion and the service operator involved.

In this context, the option of "Authorize URL" is the least relevant in confirming a SAML assertion during the IdP-initiated sign-on. The authorization URL would typically be involved in the initial connection between the user and the IdP or in redirecting the user post-authentication, but it does not play a direct role in the validation of the SAML assertion itself. The SAML assertion must be signed by the IdP, and the signature must be verifiable by the Service Provider, ensuring that the assertion has not been tampered with and originates from a trusted source.

On the other hand, the username and password would be used in an SP-initiated flow rather than IdP initiated. The IdP signature is critical as it validates that the assertion was indeed issued by the IdP, while the Service Provider signature is necessary for the relying party to validate the response it receives. Thus, the Authorize URL is not a required element for confirming the S