Steganographic Optical Camera Communication: A Framework for Secure Wireless Data Transfer

This paper introduces a novel framework for secure data transmission in optical camera communications (OCC), termed the Stega-OCC system, which integrates steganography with OCC. The proposed framework is structured into three main components: (i) the reference OCC link (OCC_RL); (ii) image acquisition and watermarking; and (iii) image recovery and data processing. A dedicated experimental testbed is developed to evaluate a 1 m long OCC_RL link, with performance analyzed in terms of the reception success rate. The data images (DIs) obtained from the OCC_RL link are embedded into cover images (CIs) using a least significant bit watermarking technique to ensure secure data embedding. In the final stage, CIs and DIs are separated, and data recovery is performed. Image quality is assessed using the peak signal-to-noise ratio and the compression quality factor with respect to the image threshold, as well as the structural similarity index measure. Further analysis of the Stega-OCC framework is conducted for various modulation frequencies of OCC. The experimental results demonstrate that the performance of the proposed system remains robust and independent of variations in modulation frequency. In summary, the developed testbed and results confirm that the Stega-OCC framework provides an effective and versatile solution for secure data transmission in OCC systems.