%% You should probably cite rfc4590 instead of this I-D.
@techreport{ietf-radext-digest-auth-09,
    number =    {draft-ietf-radext-digest-auth-09},
    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-radext-digest-auth/09/},
    author =    {Baruch Sterman and David Williams and Daniel Sadolevsky and Wolfgang Beck and David Schwartz},
    title =     {{RADIUS Extension for Digest Authentication}},
    pagetotal = 32,
    year =      2006,
    month =     may,
    day =       22,
    abstract =  {This document defines an extension to the Remote Authentication Dial-In User Service (RADIUS) protocol to enable support of Digest Authentication, for use with HTTP-style protocols like the Session Initiation Protocol (SIP) and HTTP. {[}STANDARDS-TRACK{]}},
}