A Novel Image Compression Technique and Secured Transmission of Compressed Satellite Images Via Optical Fiber Using 6D Hyper Chaos

The present work proposes an efficient optical transceiver system for secured transmission of compressed satellite images. However, most of the reported techniques fail to achieve a good balance between the compression ratio and Peak Signal to Noise (PSNR) value of the restored image maintaining system robustness against illegal eavesdropping at the same time. To improve these weaknesses, we have introduced an encryption technique combining 6D hyperchaotic sequence with random number controlled by the designed logic circuit for enciphering images before transmission. To optimize the transmission bandwidth through the optical channel, the Modified Run Length Encoding and decoding compression-decompression algorithm is used which is proven to provide a better compression ratio in comparison to existing methods. Furthermore, efficient restoration of the transmitted image with a sufficiently high PSNR and an appropriate correlation coefficient are the two crucial aspects of any authentication-based image compression technique addressed in this communication. The results are examined in terms of correlation parameter, PSNR, information entropy, histogram analysis, key sensitivity analysis, key space analysis, differential analysis and compression ratio. Robustness of the cryptosystem is verified by Known Plaintext Attack (KPA), Chosen Plaintext Attack (CPA), Chosen Ciphertext Attack (CCA), cropping attack and noise attack. Randomness of the bit stream generated by the cryptosystem is tested by the NIST SP 800-22 Randomness Test Suite. Simulation results show that the proposed technique is efficient enough for proper recovery of images with very high PSNR and correlation coefficient of value 1. The compression ratio achieved by our proposed technique is 2.008, which is proven to be much better as compared to contemporary lossless compression techniques.