A secure multimedia steganography scheme using hybrid transform and support vector machine for cloud-based storage

Cloud computing is widely accepted by both individuals and enterprises alike for the storage of multimedia contents. It is due to the introduction of a new architecture where the cost of computation, storage, and services needed for maintenance for storage of multimedia are less. Cloud computing addresses the scarcity of resources for clients by offering options to pay for services only as they are used. But once the organization's multimedia contents are uploaded into cloud space, the user loses control over their contents which may no longer be safe. The cloud user has to take some measure to avoid privacy issues. Steganography is preferred over encryption for providing multimedia security as content concealed in a cover image is not revealed. The multimedia content is transformed using Discrete Rajan Transform (DRT) and embedded into a chosen cover image which is created by Integer Wavelet using Diamond Encoding Scheme. Generated stego images are stored in the cloud. When the multimedia content is required, stego images are downloaded from the cloud and are subjected to inverse transform of IWT. SVM provides Good learning ability to our extraction process which makes our algorithm more robust to various attacks, viz., salt and pepper noise, Gaussian noise, cropping, compression, etc. Experimental values for Peak Signal to Noise Ratio (PSNR) for two secret images are 53 and 50 respectively which is better over the available schemes in the literature. Similarly for robustness and security evaluation, our scheme provides a better result.