@misc{cryptoeprint:2002:013,
    author = {Ivan Damgard and Maciej Koprowski},
    title = {Generic Lower Bounds for Root Extraction and Signature Schemes in General Groups},
    howpublished = {Cryptology ePrint Archive, Report 2002/013},
    year = {2002},
    url = {http://eprint.iacr.org/2002/013},
}