@misc{cryptoeprint:1999:009,
    author = {Satoshi Hada and Toshiaki Tanaka},
    title = {On the Existence of	3-Round Zero-Knowledge Protocols},
    howpublished = {Cryptology ePrint Archive, Report 1999/009},
    year = {1999},
    url = {http://eprint.iacr.org/1999/009},
}