@misc{cryptoeprint:2012:315,
    author = {Teng Guo and Feng Liu and ChuanKun Wu and YoungChang Hou},
    title = {Using Variance to Analyze Visual Cryptography Schemes},
    howpublished = {Cryptology ePrint Archive, Report 2012/315},
    year = {2012},
    url = {http://eprint.iacr.org/2012/315},
}