%% You should probably cite rfc2410 instead of this I-D.
@techreport{ietf-ipsec-ciph-null-00,
    number =    {draft-ietf-ipsec-ciph-null-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-ietf-ipsec-ciph-null/00/},
    author =    {K. Robert Glenn and Stephen Kent},
    title =     {{The NULL Encryption Algorithm and Its Use With IPsec}},
    pagetotal = 6,
    year =      1998,
    month =     apr,
    day =       7,
    abstract =  {This memo defines the NULL encryption algorithm and its use with the IPsec Encapsulating Security Payload (ESP). {[}STANDARDS-TRACK{]}},
}