Sujoy Sinha Roy, KU Leuven ESAT/COSIC and IMEC, Kasteelpark Arenberg 10, Leuven-Heverlee, Belgium Kimmo Järvinen, Department of Computer Science, University of Helsinki, Gustaf Hällströmin katu 2b, Helsinki, Finland Jo Vliegen, KU Leuven ESAT/COSIC and IMEC, Kasteelpark Arenberg 10, Leuven-Heverlee, Belgium Frederik Vercauteren, KU Leuven ESAT/COSIC and IMEC, Kasteelpark Arenberg 10, Leuven-Heverlee, Belgium Ingrid Verbauwhede, KU Leuven ESAT/COSIC and IMEC, Kasteelpark Arenberg 10, Leuven-Heverlee, Belgium