Cryptology ePrint Archive: BibTeX Citation of Report 2015/675

@misc{cryptoeprint:2015:675,
    author = {Ahmed Kosba and Andrew Miller and Elaine Shi and Zikai Wen and Charalampos Papamanthou},
    title = {Hawk: The Blockchain Model of Cryptography and Privacy-Preserving Smart Contracts},
    howpublished = {Cryptology ePrint Archive, Report 2015/675},
    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.