Goichiro Hanaoka Kazuto Ogawa Itsuro Murota Go Ohtake Keigo Majima Seiichi Gohshi Kimiyuki Oyamada Seiichi Namba Hideki Imai Managing Encryption and Key Publication Independently in Digital Rights Management Systems. 160-172 http://search.ieice.org/bin/summary.php?id=e87-a_1_160&category=D&year=2004&lang=E&abst= 2004 87-A IEICE Transactions 1 db/journals/ieicet/ieicet87a.html#HanaokaOMOMGONI04