@misc{cryptoeprint:2004:298,
    author = {Zuo-Wen Tan,Zhuo-Jun Liu},
    title = {Nominative Proxy Signature Schemes},
    howpublished = {Cryptology ePrint Archive, Report 2004/298},
    year = {2004},
    url = {http://eprint.iacr.org/2004/298},
}