%% You should probably cite rfc3664 instead of this I-D.
@techreport{ietf-ipsec-aes-xcbc-prf-01,
    number =    {draft-ietf-ipsec-aes-xcbc-prf-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-ipsec-aes-xcbc-prf/01/},
    author =    {Paul E. Hoffman},
    title =     {{The AES-XCBC-PRF-128 Algorithm for the Internet Key Exchange Protocol (IKE)}},
    pagetotal = 4,
    year =      2003,
    month =     oct,
    day =       9,
    abstract =  {Some implementations of IP Security (IPsec) may want to use a pseudo-random function derived from the Advanced Encryption Standard (AES). This document describes such an algorithm, called AES-XCBC-PRF-128.},
}