  Confidentiality was and will always remain a critical need in the exchanges
either between persons or the official parties. Recently, cryptology has made a
jump, from classical form to the quantum one, we talk about quantum
cryptography. This theory, although is perfectly safe, there are still binding
limits of implementation. In this paper, we developed a new cryptographic
protocol, called BCB12 protocol, which will be used to provide random keys
shared via a classical channel, using the set partitions. Each key can be long
enough that the plain text in question, in purpose, for instance, to hide then
to transmit the secret information using the Vernam cipher.
