Cryptology ePrint Archive: BibTeX Citation of Report 2006/051

@misc{cryptoeprint:2006:051,
    author = {Shigeo Tsujii and Kohtaro Tadaki and Ryou Fujita},
    title = {Proposal for Piece In Hand Matrix Ver.2: General Concept for Enhancing Security of Multivariate Public Key Cryptosystems},
    howpublished = {Cryptology ePrint Archive, Report 2006/051},
    year = {2006},
    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.