%% You should probably cite draft-ietf-mip4-rfc3012bis instead of this I-D.
@techreport{ietf-mobileip-rfc3012bis-05,
    number =    {draft-ietf-mobileip-rfc3012bis-05},
    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-mobileip-rfc3012bis/05/},
    author =    {Charles E. Perkins and Jayshree A. Bharatia},
    title =     {{Mobile IPv4 Challenge/Response Extensions (revised)}},
    pagetotal = 23,
    year =      2004,
    month =     aug,
    day =       24,
    abstract =  {Mobile IP, as originally specified, defines an authentication extension (the Mobile-Foreign Authentication extension) by which a mobile node can authenticate itself to a foreign agent. Unfortunately, that extension does not provide the foreign agent any direct guarantee that the protocol is protected from replays, and does not allow for the use of CHAP for authenticating portable computer devices. In this specification, we define extensions for the Mobile IP Agent Advertisements and the Registration Request that allow a foreign agent to use a challenge/response mechanism to authenticate the mobile node. This document obsoletes RFC 3012.},
}