@misc{cryptoeprint:2004:326,
    author = {Zhengjun Cao},
    title = {Cryptanalysis of Qiu-Gu-Chen  Variant Group Signature Scheme},
    howpublished = {Cryptology ePrint Archive, Report 2004/326},
    year = {2004},
    url = {http://eprint.iacr.org/2004/326},
}