@misc{cryptoeprint:2009:631,
    author = {DaeHun Nyang and Mun-Kyu Lee },
    title = {Improvement of Das's Two-Factor Authentication Protocol in Wireless Sensor Networks},
    howpublished = {Cryptology ePrint Archive, Report 2009/631},
    year = {2009},
    url = {http://eprint.iacr.org/2009/631},
}