Sponsors
Quantum computers threaten to break most of the cryptography we currently use to protect our information security systems over an insecure channel such as the internet. In a quantum computer, performing operations comes from a quantum physical notion that works differently from a classical computer setting, and it gives an exponential speed-up for certain computations. The question of when a large-scale quantum computer will be built is not known and it is hard to estimate the exact time. Although it was not clear that large quantum computers were physically possible in the past, many scientists nowadays believe that it is just a significant engineering challenge. Currently, many researchers have been working to create quantum- resistant cryptographic systems by the time they are needed due to the sudden realization of the possible near arrival of a general quantum computer within the cryptographic community. If large quantum computers become practical one day, all widely used methods of asymmetric cryptography in use will be essentially broken. While the most optimistic believers of quantum computers suggest that such computers are years away to be constructed, maybe decades, it also takes years, maybe decades, to develop, test, and deploy new quantum-resistant schemes. To construct such quantum-resistant cryptographic systems, we need a new class of hard mathematical problems which seem to be unbreakable even by a quantum computer. Many of the problems supposed and believed to be hard for quantum computers have been used for constructing new quantum-resistant protocols, and they are currently competing in the National Institute of Standards and Technology (NIST) Post Quantum Cryptography Standardization. These proposed schemes can be described with their corresponding underlying mathematical problems as follows: