@misc{cryptoeprint:2002:173,
    author = {Giuseppe Ateniese and Breno de Medeiros},
    title = {Efficient Group Signatures without Trapdoors},
    howpublished = {Cryptology ePrint Archive, Report 2002/173},
    year = {2002},
    url = {http://eprint.iacr.org/2002/173},
}