DRAFT, with many questions
Technical implementation of assurance requires system changes from InCommon Ops, IdPs, and SPs. There are many different scenarios and choices.
InCommon Ops will add IAQs to the published metadata following notification of certification by InCommon management. These will apply to the relevant IdP entries of the certified IdPOs. IAQ URIs are:
Ideally SPs will initiate the assurance flow by including the desired IAQ in the SAML AuthnRequest element.
SPs will receive IAQs (either in response to a request, or sent unsolicited) in assertions from IdPs. SPs should use metadata for the relevant IdPs to check that they are certified to assert the IAQs they're asserting.
SPs will use local policy to decide how to handle incoming IAQs. For example if the SP requires InCommon Bronze but receives InCommon Silver that should be acceptable.
Ideally IdPs will receive a desired IAQ from an SP in an AuthnRequest to initiate the process. The IdP deals with the requested IAQ and matching rule and interacts with the local IdM system to determine if the user at hand meets the requirements. If so the appropriate IAQ is returned in the AuthnContext element in the assertion.
SPs may not put IAQs in AuthnRequests but still want to see IAQs from IdPs.