Cryptology ePrint Archive: BibTeX Citation of Report 2004/212

@misc{cryptoeprint:2004:212,
    author = {Danfeng Yao and Nelly Fazio and Yevgeniy Dodis and Anna Lysyanskaya},
    title = {ID-Based Encryption for Complex Hierarchies with Applications to Forward Security and Broadcast Encryption},
    howpublished = {Cryptology ePrint Archive, Report 2004/212},
    year = {2004},
    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.