Quantum networks connect multiple users and quantum devices, opening the door to new cryptographic and information processing tasks that cannot be achieved, or at least cannot be achieved as efficiently, using conventional bipartite protocols.

Our research investigates how multipartite quantum correlations can be used as resources for communication and cryptography in the network scenario. We study protocols that go beyond secure communication, such as, for example, anonymous communication, where several users must coordinate while keeping sensitive information hidden from other parties in the network.

A major focus is understanding which resources are necessary to perform these tasks and how these protocols behave in realistic and adversarial settings. Multipartite systems exhibit a much richer structure of quantum correlations than bipartite systems, including different types of entanglement and genuinely multipartite correlations. This richness can provide new functionality, but it also makes the security analysis substantially more challenging.