Cryptology ePrint Archive: BibTeX Citation of Report 2011/455

@misc{cryptoeprint:2011:455,
    author = {Jie Chen and Hoon Wei Lim and San Ling and Huaxiong Wang},
    title = {The Relation and Transformation between Hierarchical Inner Product Encryption and Spatial Encryption},
    howpublished = {Cryptology ePrint Archive, Report 2011/455},
    year = {2011},
    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.