Privacy-Preserving Data Mashup Benjamin C.M. Fung Concordia University Montreal, QC, Canada [email protected] dia.ca Noman Mohammed Concordia University Montreal, QC, Canada [email protected] dia.ca Ke Wang Simon Fraser University Burnaby, BC, Canada [email protected] Patrick C. K. Hung UOI T Oshawa, ON, Canada patrick.hung@uoit .ca EDBT 2009