%% You should probably cite rfc7619 instead of this I-D.
@techreport{ietf-ipsecme-ikev2-null-auth-01,
    number =    {draft-ietf-ipsecme-ikev2-null-auth-01},
    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-ipsecme-ikev2-null-auth/01/},
    author =    {Valery Smyslov},
    title =     {{The NULL Authentication Method in IKEv2 Protocol}},
    pagetotal = 10,
    year =      2014,
    month =     oct,
    day =       22,
    abstract =  {This document introduces the NULL authentication method for the IKEv2 Protocol. This method provides a way to omit peer authentication in the IKEv2. It may be used to preserve anonymity of or in the situations, where no trust relationship exists between the parties.},
}