%% You should probably cite draft-ietf-avt-srtp-big-aes instead of this I-D.
@techreport{mcgrew-srtp-big-aes-01,
    number =    {draft-mcgrew-srtp-big-aes-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-mcgrew-srtp-big-aes/01/},
    author =    {David McGrew},
    title =     {{The use of AES-192 and AES-256 in Secure RTP}},
    pagetotal = 17,
    year =      2009,
    month =     mar,
    day =       5,
    abstract =  {This memo describes the use of the Advanced Encryption Standard (AES) with 192 and 256 bit keys within the Secure RTP protocol. It defines Counter Mode encryption for SRTP and SRTCP and a new SRTP Key Derivation Function (KDF) for AES-192 and AES-256.},
}