Zekeriya Erkin Martin Franz Jorge Guajardo Stefan Katzenbeisser Inald Lagendijk Tomas Toft Privacy-Preserving Face Recognition. 235-253 2009 Privacy Enhancing Technologies http://dx.doi.org/10.1007/978-3-642-03168-7_14 conf/pet/2009 db/conf/pet/pets2009.html#ErkinFGKLT09