Emiliano De Cristofaro Stanislaw Jarecki Jihye Kim Gene Tsudik Privacy-Preserving Policy-Based Information Transfer. 164-184 2009 Privacy Enhancing Technologies http://dx.doi.org/10.1007/978-3-642-03168-7_10 conf/pet/2009 db/conf/pet/pets2009.html#CristofaroJKT09