Securing today’s data against tomorrow’s enemies.
Digital communications are currently protected by asymmetric cryptography technology. Peter Shor has shown that a powerful quantum computer could break current encryption. What would happen if some of today’s top-secret information, such as diplomatic negotiations, financial transactions or even health data, were to be leaked in 5, 10 or even 20 years’ time? To combat this threat, cryptographers must accept that they are not fighting on an equal playing field. They must find a way to protect information from future quantum enemies with today’s classical computers. The underlying scientific challenge is to find simple mathematical operations that can be performed on everyone’s devices and which cannot be undone by an inordinate amount of computing power. One way to model these new problems is to imagine a grid and a token. It is easy to decide whether the token is close to the grid. But if now, instead of being given the grid, you are only given a few points close to it along with the token. In that case, it is much more difficult to determine whether the token is in a reasonable vicinity of the grid. At the end of 2016, the American National Institute of Standards and Technology (NIST) launched an international competition since to look for future post-quantum standards and has since received 69 valid proposals. After three selection rounds over several years, two of XLIM’s algorithms (BIKE and HQC) are among the nine finalists for the cryptography of tomorrow.