Novel Approach for fast Compressed Hybrid color image Cryptosystem

In this Paper, the issues pertaining with efficient, fast, cost effective and secured image transmission are addressed in totality. The proposed model employs Compressed Hybrid Cryptosystem constitutes compression, encryption and secured session key exchange along with the transmission of image. In the proposed work, an algorithm has been designed to generate diffusion template using 3D Standard map. The image is rotated vertically and horizontally followed by a shuffle using 3D Cat map and Standard map. The image is then encrypted by performing XOR operation on the shuffled image and diffusion template. Proposed method takes lesser time and is found to be safe from any of the existing cryptanalytic attack. Further Elliptic Curve Cryptography is used for secure transfer of private key, which has resulted in significant reduction in the key size without compromising its security strength. To reduce bandwidth requirement and power consumption, a compression technique is proposed based on curvelet transform before image encryption, with special technique of coefficient elimination by which a higher compression ratio can be obtained without much loss in image information. Even though the coefficients neglected are large, the higher PSNR values show that curvelet has better reconstruction performance. The model has been rigorously examined over the prevalent standard test and has encouragingly succeeded to pass most of them like key sensitivity analysis, key space analysis, statistical analysis, differential analysis, entropy analysis, randomness analysis, PSNR analysis, MSE analysis, for fast, cost effective and secured image transmission. Which was the key problem statement for this research work. (C) 2012 Elsevier Ltd. All rights reserved.