%% You should probably cite draft-ietf-krb-wg-otp-preauth instead of this I-D.
@techreport{richards-otp-kerberos-03,
    number =    {draft-richards-otp-kerberos-03},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-richards-otp-kerberos/03/},
    author =    {Gareth Richards},
    title =     {{OTP Kerberos}},
    pagetotal = 17,
    year =      2007,
    month =     jun,
    day =       26,
    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.},
}