Cryptology ePrint Archive: BibTeX Citation of Report 2015/397

@misc{cryptoeprint:2015:397,
    author = {Peter Gazi and Jooyoung Lee and Yannick Seurin and John Steinberger and Stefano Tessaro},
    title = {Relaxing Full-Codebook Security: A Refined Analysis of Key-Length Extension Schemes},
    howpublished = {Cryptology ePrint Archive, Report 2015/397},
    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.