Abstract

With the recent enormous advancement in networking technology, it has become elementary to transfer data across the network. Within a brief period, the files are being distributed to millions of people living throughout the globe. Regarding the legalization and protection of shared data, this presents several issues. The files can be easily duplicated, transmitted, and used for purposes other than what was intended, resulting in legal matters and social unrest and jeopardizing the owner's rights. A watermark's presence can guarantee the digital content's validity and aid in copyright protection. This research work introduces three digital watermarking mechanisms for keeping copyright protection. The purpose of suggesting these watermarking methods is to distract the invader trying to unshielded the watermark. These three methods will act like a switching technique. In the 1stmethod, the DWT decomposes the host and watermark images into LL and HH sub-bands, fetches the singular valuesthrough SVD, and then embeds those duo images. The 2ndmethod inserts the watermark directly into the LL sub-band of the modified host image. The watermark is extracted here from the reverse order. In the 3rd method, the watermark is altered and added to the LH and HL sub-bands of the host image. The findings of PSNR values of LL-HH sub-bands are 43.8362 for grayscale and 36.0 (Average) for color images. Besides, the LL sub-band, which exerts in the 2ndmethod, observes 41.3853 (PSNR) for color images, andthe blend of LH-HL sub-bands detects a PSNR value of 45.0 (Average) for grayscale images. The 1stmethod contributes better performance for greyscale and color images, whereas the 2nd method is preferred only for color images and the 3rd for greyscale images.Furthermore, steganography is practiced nowadays for information hiding capacity rather than cryptography. Although cryptography encodes data in an unreadable format and the individual can see its presence, hence the invader could try to retrieve the original form of the message if he or she wants to misuse it. The visibility of messages in cryptographic format manipulate to apply the steganography method. Steganography hides the secret message within the carrier; thus, none can sense the presence ofconfidential information. Various steganography methods have been developed considering the precedence of hiding secret message issues. But most techniques are inadequate for undetectability and security for conventional attacks. This research work also announces a novel steganography approach that uses Arnold transform to scramble the secret image and applies SVD to compute the principal components of the scrambled image. However, the cover image is also adjusted by NSCT and QR factorization. The scattered image's principal components insert into the cover image's R matrix. The data hiding capability of this method is 70.86 in PSNR. The watermarking methods are tested to show imperceptibility and robustness, and the steganography method is executed to prove its undetectability and security. The hypothetical results show sustainable invisibility for steganography's watermarking and data hiding capability. Moreover, the watermarking and steganography mechanisms are robust and secure against attacks. Keywords:Digital watermarking; Steganography; Discrete wavelet transform (DWT); Singular value decomposition (SVD); QR factorization; non-subsampled contourlet transform (NSCT); Imperceptibility; Robustness.