1. EPFL, Lausanne, Switzerland
2. Google. This work was carried out while the author was with EPFL, Lausanne, Switzerland .
3. University of Lausanne, Lausanne, Switzerland
4. Stanford University, Stanford, United States of America . This work was carried out while the author was with EPFL, Lausanne, Switzerland .
5. CMU, Pittsburgh, United States of America
6. Jean-Pierre Hubaux: EPFL, Lausanne, Switzerland