Nowadays, the secure communication problem represents one of the main challenges cryptography faces. It consists of providing a way for two distant parties to privately communicate over a shared channel, even in presence of an eavesdropper. Arguably, the One-time-pad (OTP) could represent a perfect cypher that will allow solving the aforementioned problem providing a way to achieve perfectly secure communication. However, for the OTP scheme to be applicable, the two communicating parties need to establish a shared key and each to have their copy; achieving such a purpose while an eavesdropper is present on the channel represents a whole new problem: the key distribution problem.