Cryptology ePrint Archive: BibTeX Citation of Report 2015/978

@misc{cryptoeprint:2015:978,
    author = {Hugo Krawczyk and Hoeteck Wee},
    title = {The OPTLS Protocol and TLS 1.3},
    howpublished = {Cryptology ePrint Archive, Report 2015/978},
    year = {2015},
    note = {\url{http://eprint.iacr.org/}},
}

You will need the url.sty package (comes with most LaTeX installations) for the last line. Otherwise, remove the \url command.