%% You should probably cite rfc9470 instead of this I-D.
@techreport{ietf-oauth-step-up-authn-challenge-17,
    number =    {draft-ietf-oauth-step-up-authn-challenge-17},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-ietf-oauth-step-up-authn-challenge/17/},
    author =    {Vittorio Bertocci and Brian Campbell},
    title =     {{OAuth 2.0 Step Up Authentication Challenge Protocol}},
    pagetotal = 14,
    year =      2023,
    month =     jun,
    day =       26,
    abstract =  {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.},
}