White-light interferometric method for secure key distribution

A protocol for secure key distribution using classical light is proposed. The method relies on white-light interferometric measurements by one of the communicating parties and the random choice of delays by the other party. In this way, securely shared random keys are created, thereby enabling secure data transmission. In contrast to quantum key distribution, only classical waves are used. Single photons (and the practical problems associated with them) are avoided. The security of the method cannot be proven at the moment but different attacks are described and briefly analyzed.