Yumiko Hanaoka Goichiro Hanaoka Junji Shikata Hideki Imai Unconditionally Secure Key Insulated Cryptosystems: Models, Bounds and Constructions. 85-96 2002 conf/icics/2002 ICICS http://link.springer.de/link/service/series/0558/bibs/2513/25130085.htm db/conf/icics/icics2002.html#HanaokaHSI02