Speaker
Description
Measurement in quantum mechanics is of probabilistic nature. Furthermore, in a given state of a quantum system, it is impossible to measure the value of two (noncommuting) observables without disturbing the state. These features of quantum mechanics provide a way of generating a sequence of correlated random numbers at distant places, where any disturbance by an unfriendly agent can be detected by comparing some of the measurement results. An identical series of random numbers at the hand of distant parties is known to be very useful for cryptographic purposes. One can either employ one-time pad cryptography to absolutely securely send an encrypted message through a public channel or apply a symmetric key encryption for the same purpose. The above ideas can be realized by various quantum protocols. Commercial telecom fibers or satellite connections may both serve as channels for quantum communication. One can already find quantum key distribution (QKD) systems on the market. We plan to deploy a few nodes in Hungary to test the how a larger QKD network can be built up, which later could be part of a pan-European quantum communication network.
