PHC Sakura

Set up in collaboration with the University of Electro-Communications in Tokyo, this international project is specifically designed to encourage Franco-Japanese collaborations. The concepts of “Scale-based cryptography” and “Card-based cryptography” are innovative approaches in which zero-knowledge proof physical protocols can be realized by modeling Roberval-type physical scales or decks of cards. By means of multiple comparisons, we can model basic logic functions such as AND and OR operations, and thus build complex protocols in which it is possible to verify that someone knows a secret without having to reveal it. In particular, game modeling can be used to study game-theoretic problems that can be extended to real-life problems. These concepts may seem simplistic in the light of existing cryptographic mechanisms, but they take on their full significance when we consider problems in which computers are not used, such as voting in France (paper and ballot box).