OAuth 2.0 Step Up Authentication Challenge Protocol
RFC 9470

Received changes through RFC Editor sync (created alias RFC 9470, changed title to 'OAuth 2.0 Step Up Authentication Challenge Protocol', changed abstract to 'It is not uncommon for resource servers to require different authentication strengths or recentness according to the characteristics of a request.  This document introduces a mechanism that resource servers can use to signal to a client that the authentication event associated with the access token of the current request does not meet its authentication requirements and, further, how to meet them.  This document also codifies a mechanism for a client to request that an authorization server achieve a specific authentication strength or recentness when processing an authorization request.', changed pages to 14, changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2023-09-08, changed IESG state to RFC Published)