Noisy quantum cryptography

First we provide a general introduction to quantum-related activities at Eötvös Loránd University, Faculty of Informatics (Budapest, Hungary). Next a selected topic, noisy quantum cryptography is presented in more details. In particular, we focus on quantum key destribution (QKD) and quantum secret sharing (QSS).

QKD is a way to exchange symmetric keys between two distant parties with the laws of quantum mechanics ensuring that evesdropping can be detected. Secret sharing serves to distribute secret information in such a way that only a selected number of participants can recover the secret, individual participants can gain no information. QSS also uses the principles of quantum mechanics to enhance security of secret sharing.

Publications on quantum cryptography usually ignore noise, and because of that, security of published and well-known protocols might be compromised. In the talk, we explore noisy quantum channels and their effect on QKD and QSS building on entangled Bell pairs. Finally, we explore a noisy version of a recently published entanglement distillation protocol.