Wen Ping Ma Moon Ho Lee New Methods to Construct Cheating Immune Functions. 79-86 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2971&spage=79 2003 conf/icisc/2003 ICISC db/conf/icisc/icisc2003.html#MaL03