  One-time-pad (OTP) encryption simply cannot be cracked, even by a quantum
computer. The need of sharing in a secure way supplies of symmetric random keys
turned the method almost obsolete as a standing-alone method for fast and large
volume telecommunication. Basically, this secure sharing of keys and their
renewal, once exhausted, had to be done through couriers, in a slow and costly
process. This paper presents a solution for this problem providing a fast and
unlimited renewal of secure keys: An untappable key distribution system is
presented and detailed. This fast key distribution system utilizes two layers
of confidentially protection: 1) Physical noise intrinsic to the optical
channel that turn the coded signals into stealth signals and 2) Privacy
amplification using a bit pool of refreshed entropy run after run, to eliminate
any residual information.
  The resulting level of security is rigorously calculated and demonstrates
that the level of information an eavesdropper could obtain is completely
negligible. The random bit sequences, fast and securely distributed, can be
used to encrypt text, data or voice.
