Secure Encryption then Compression Systems using Encryption Algorithms

Abstract

A new grayscale-based block scrambling image encryption algorithm is introduced to enhance the security of Encryption-then-Compression (EtC) systems, which are used to securely transmit images over an untrusted channel provider. This algorithm is designed to improve the security of Encryption-then-Compression (EtC) systems. A smaller block size and a greater number of blocks are possible with the proposed scheme in comparison to the new encryption system. In spite of the fact that the original image contains three colour channels, photos encrypted using the suggested approach contain less colour information because grayscale images are used to encrypt the information. These features, among other things, improve security against threats such as jigsaw puzzle solvers and brute-force assaults, among others. Apart from that, even though the encrypted photos do not contain any colour information, it allows for colour sub-sampling, which can increase the compression speed of the photos. In an experiment, encrypted photos were uploaded to and then downloaded from social networking sites, and the results revealed that the suggested approach is successful for ETC systems while still maintaining excellent compression performance by utilising advanced compression algorithms.