Alberto Munoz

The latest advances in quantum computing forced the National Institute of Standards and Technology (NIST) to launch an initiative for selecting quantum-resistant cryptographic algorithms. One of the best-known proposals is NewHope, an algorithm that was initially designed as a key exchange algorithm. In its original design, NewHope presented a reconciliation mechanism that is complex and represents an entry barrier for potential implementers. This contribution presents equivalent schemes in one, two and three dimensions, which allow anyone to make the transition to the 4D NewHope algorithm easier to undertake. In addition to that, the effect of modifying some of the parameters associated to NewHope’s reconciliation mechanism is studied, which has allowed us to propose different sets of parameters that could increase the security of NewHope implementations.

Nowadays, the high-temperature plasticity of yttria-stabilized tetragonal zirconia polycrystals is successfully explained in terms of a threshold stress. Despite the fact that its existence is very well proved experimentally, the origin and nature of the threshold stress are still unexplained. This work develops a possible explanation for the threshold stress in YTZPs. The model developed in this paper is able to explain quantitatively the dependence of this threshold stress with temperature and grain size. The model is able to predict the influence of a glassy phase present at grain boundaries and the values of the threshold stress in YTZP nanocrystals. The theoretical results are discussed and compared with the available data in the literature