Understanding quantum key distribution
Most widely used classical cryptographic algorithms rely on the assumption that an attacker cannot easily solve hard mathematical problems due to the limitation of their computational power. However, some quantum algorithms, such as Shor's factorization of integers, could break this assumption should a large enough quantum computer be built one day.
The goal of quantum cryptography is thus to design new cryptographic techniques that make use of the properties of quantum mechanics, such as the no-cloning theorem and the Heisenberg uncertainty principle, to build secure systems. Thus, unlike its classical counterpart, quantum cryptography does not need computational assumptions to defend against attacks, but relies instead on the laws of quantum physics.
Several protocols have been defined to tackle quantum key distribution, the two most famous being BB84 introduced by Charles H. Bennett and Gilles Brassard in 1984 and E91 introduced...