Untappable Key Distribution System: a One-Time-Pad Booster

Abstract

The One-Time-Pad (OTP) protocol gives unconditional security for the information being encrypted. Correctly implemented, not even an adversary with a quantum computer can crack it. However, the need of sharing in a secure way supplies of symmetric random keys turned the method almost obsolete as a stand-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 negligible. The random bit sequences, fast and securely distributed, can be used to encrypt text, data or voice.