Yevgeniy Dodis Nelly Fazio Public Key Broadcast Encryption for Stateless Receivers. 61-80 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2696&spage=61 2002 conf/ccs/2002drm Digital Rights Management Workshop db/conf/ccs/ccsdrm2002.html#DodisF02