BB84 was the first studied and practical implemented QKD physical layer protocol. It was elaborated by Charles Bennet and Gilles Brassard in 1984 in their article [2]. It is surely the most famous and most realized quantum cryptography protocol. This scheme uses the transmission of single polarized photons (as the quantum states). The polarizations of the photons are four, and are grouped together in two different non orthogonal basis.