@TechReport{pido,
  author =	 {Gang Liang and Sudarshan S. Chawathe},
  title =	 {Privacy-Preserving Inter-Database Operations},
  institution =	 {University of Maryland, College Park},
  year =	 2004,
  number =	 {CS-TR-4564 (UMIACS-TR-2004-09)},
  month =	 Feb,
  annote =	 {Privacy-preserving intersections and joins, using
                  asymmetric protocols.}
}