@misc{cryptoeprint:2009:344,
    author = {Xi Zhang and  Min-Rong Chen and Xia Li},
    title = {Comments on Shao-Cao's Unidirectional Proxy Re-Encryption Scheme  from PKC 2009},
    howpublished = {Cryptology ePrint Archive, Report 2009/344},
    year = {2009},
    url = {http://eprint.iacr.org/2009/344},
}