Securing 2D information carriers over dynamic and turbulent media in a free-space optical channel

In this Letter, a new, to the best of our knowledge, scheme is proposed to realize high-fidelity secured free-space optical information transmission through dynamic and turbulent media by encoding 2D information carriers. The data are transformed into a series of 2D patterns as information carriers. A novel differential method is developed to suppress noise, and a series of random keys are also generated. A different number of absorptive filters are arbitrarily combined to be placed in the optical channel to generate ciphertext with high randomness. It is experimentally demonstrated that the plaintext can be retrieved only when correct security keys are applied. Experimental results demonstrate that the proposed method is feasible and effective. The proposed method provides an avenue for securing high-fidelity optical information transmission over dynamic and turbulent media in a free-space optical channel.