We have designed algorithms to obtain certified bounds on the security of protocols in quantum cryptography. This tool can be used to automatically search for protocols that are adapted to the actual quantum devices, for example protocols that can tolerate higher levels of noise. In addition, at the mathematical level, we have significantly generalised the tool known as "entropy accumulation" to be applicable to analyse the security of a wider class of protocols. We expect that entropy accumulation will become one of the main tools used to establish security of a given scheme. In terms of communication networks, we gave evidence that quantum entanglement has the potential of significantly increasing the communication capacities of a classical communication network.
Regarding quantum computation in the presence of faults, we have established fundamental limitations on the tradeoff between memory, time and the geometry of the quantum computation architecture. Moreover, we developed an algorithmic tool to determine bounds on how much information can be stored in a quantum device given a mathematical model of this device.