@misc{cryptoeprint:2009:139,
    author = {Chunbo Ma and Jun Ao},
    title = {Certificateless Group Oriented Signature Secure Against Key Replacement Attack},
    howpublished = {Cryptology ePrint Archive, Report 2009/139},
    year = {2009},
    url = {http://eprint.iacr.org/2009/139},
}