On the Security of Multiple Encryption or CCA-security+CCA-security=CCA-security?

Rui Zhang 0002 Goichiro Hanaoka Junji Shikata Hideki Imai On the Security of Multiple Encryption or CCA-security+CCA-security=CCA-security? 360-374 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2947&spage=360 2004 conf/pkc/2004 Public Key Cryptography db/conf/pkc/pkc2004.html#ZhangHSI04