@INPROCEEDINGS{cgUCL-HQ98,
 	AUTHOR={Hou, S. and Quisquater, Jean-Jacques},
	TITLE={{Audio and Optical Cryptography}},
	BOOKTITLE={Proceedings of Asiacrypt'98},
	PUBLISHER={Springer-Verlag},
	EDITOR={K. Ohta and D. Pei},
	SERIES={Lecture Notes in Computer Science},
	VOLUME={1514},
	PAGES={392-404},
	MONTH={1},
	YEAR={1998},
}