%% You should probably cite rfc6560 instead of this I-D.
@techreport{ietf-krb-wg-otp-preauth-21,
    number =    {draft-ietf-krb-wg-otp-preauth-21},
    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-krb-wg-otp-preauth/21/},
    author =    {Gareth Richards},
    title =     {{One-Time Password (OTP) Pre-Authentication}},
    pagetotal = 43,
    year =      2011,
    month =     nov,
    day =       23,
    abstract =  {The Kerberos protocol provides a framework authenticating a client using the exchange of pre-authentication data. This document describes the use of this framework to carry out One-Time Password (OTP) authentication. {[}STANDARDS-TRACK{]}},
}