@inproceedings{lhasp04,
   author = {Leonardo B. Oliveira and Hao Chi Wong and Antonio A. F. Loureiro and Daniel Barbosa},
   title = {A Security Protocol for Hierarchical Sensor Networks},
   booktitle = {Proceedings of the 22nd Brazilian Symposium on Computer Networks ({SBRC'04})},
   month = {May},
   address = {Gramado, Brazil},
   pages = {175--188},
   year = {2004},
   note = {{ISBN 85-88442-80-9}}
}