Ping Lin K. Selçuk Candan Secure and Privacy Preserving Outsourcing of Tree Structured Data. 1-17 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3178&spage=1 2004 conf/sdmw/2004 Secure Data Management db/conf/sdmw/sdmw2004.html#LinC04