Jorge Nakahara Jr. Daniel Santana de Freitas 206-217 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3348&spage=206 2004 conf/indocrypt/2004 INDOCRYPT db/conf/indocrypt/indocrypt2004.html#NakaharaF04