%% You should probably cite draft-ietf-ipsecme-esp-null-heuristics instead of this I-D.
@techreport{kivinen-ipsecme-esp-null-heuristics-00,
    number =    {draft-kivinen-ipsecme-esp-null-heuristics-00},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-kivinen-ipsecme-esp-null-heuristics/00/},
    author =    {Tero Kivinen and Daniel McDonald},
    title =     {{Heuristics for Detecting ESP-NULL packets}},
    pagetotal = 33,
    year =      2009,
    month =     jan,
    day =       22,
    abstract =  {This document describes a heuristic approach for distinguishing ESP- NULL (Encapsulating Security Payload without encryption) packets from encrypted ESP packets. The reason for using heuristics instead of modifying ESP is to provide a solution that can be used now without updating all end nodes. With heuristic methods, only the intermediate devices wanting to find ESP-NULL packets need to be updated.},
}