@inproceedings{XLESZ:03,
title = {{Mandatory Human Participation: A New Authentication Scheme for Building Secure Systems}},
author = {Jun Xu and Richard Lipton and Irfan Essa and Minho Sung and Yong Zhu},
booktitle = {{Proceedings of the 12th International Conference on Computer Communication and Networks (ICCCN)}},
month = Oct,
year = 2003
}