%% You should probably cite draft-ietf-tls-chacha20-poly1305 instead of this I-D.
@techreport{mavrogiannopoulos-chacha-tls-04,
    number =    {draft-mavrogiannopoulos-chacha-tls-04},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-mavrogiannopoulos-chacha-tls/04/},
    author =    {Adam Langley and Wan-Teh Chang and Nikos Mavrogiannopoulos and Joachim Strombergson and Simon Josefsson},
    title =     {{The ChaCha Stream Cipher for Transport Layer Security}},
    pagetotal = 7,
    year =      2014,
    month =     dec,
    day =       12,
    abstract =  {This document describes the use of the ChaCha stream cipher with Poly1305 in Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS) protocols.},
}