Michael Epstein Laszlo Hars Raymond Krasinski Martin Rosner Hao Zheng Design and Implementation of a True Random Number Generator Based on Digital Circuit Artifacts. 152-165 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2779&spage=152 2003 conf/ches/2003 CHES db/conf/ches/ches2003.html#EpsteinHKRZ03