%% You should probably cite rfc9175 instead of this I-D.
@techreport{ietf-core-echo-request-tag-02,
    number =    {draft-ietf-core-echo-request-tag-02},
    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-core-echo-request-tag/02/},
    author =    {Christian Amsüss and John Preuß Mattsson and Göran Selander},
    title =     {{Echo and Request-Tag}},
    pagetotal = 21,
    year =      ,
    month =     ,
    day =       ,
    abstract =  {This document specifies several security enhancements to the Constrained Application Protocol (CoAP). Two optional extensions are defined: the Echo option and the Request-Tag option. Each of these options provide additional features to CoAP and protects against certain attacks. The document also updates the processing requirements on the Token of {[}RFC7252{]}. The updated Token processing ensures secure binding of responses to requests.},
}