We propose and numerically demonstrate a high-rate secure key distribution scheme based on private chaos synchronization of two semiconductor lasers subject to common driving injection and an alternating step algorithm (ASA). By exchanging the random control parameters that correspond to different feedback delays of local external-cavity semiconductor lasers, the legitimate users Alice and Bob can identify the time slots in which high-quality private chaos synchronization is achieved. Based on this property, a true random seed key can be independently and privately generated by Alice and Bob, in virtue of symmetric post-processing. Moreover, an ASA is designed to generate a new high-rate key as the final key. By the ASA iterations, random final key distribution with an extended rate significantly higher than that of the seed key can be achieved. The feasibility and performance of the proposed high-rate secure key distribution scheme are verified by numerical simulations. This work provides a high-level security and high-rate random key distribution scheme that has the potential to implement one-time-pad encryption in high-speed secure optical communications.
High-Rate Secure Key Distribution Based on Private Chaos Synchronization and Alternating Step Algorithms
