Extended visual cryptography-based copyright protection scheme for multiple images and owners using LBP–SURF descriptors

Abstract

Existing visual cryptography (VC)-based copyright protection schemes (Amiri and Mohaddam in Multimed Tools Appl 75(14):8527–8543, 2016; Liu and Wu in IET Inf Secur 5(2):121–128, 2011) for multiple images provide meaningless shares to the owners. These shares create a suspicion that some secret information is shared. Also, these schemes require the share of every owner to prove the copyright. If any of the ownership share is not available, the copyright of these owners cannot be verified. This makes the usage of schemes restricted. To address these issues, an extended visual cryptography-based copyright protection scheme is proposed for multiple images with multiple owners. This scheme provides meaningful ownership shares to the owners, and their copyright can be verified by using a qualified set of owner shares. In this scheme, three types of shares are used, i.e., master share, ownership share and key share. The proposed scheme ensures robustness against different geometrical attacks, especially the rotation attack, as LBP and SURF together represent the host image efficiently. There is no restriction on watermark size, as SURF gives a flexibility to select any number of feature points. Usage of LBP ensures no false positive cases. Each of the ownership shares is created using the master share and the watermark. The ownership share is used to create a key share which is stored with the Trusting Authority (TA). To prove the copyright of multiple images, the ownership images and key share are superimposed to retrieve the watermark. The experimental results show that the scheme clearly verifies the copyright of digital images and is robust against several image processing attacks while having high imperceptibility. Comparisons with the existing copyright protection schemes show better performance of the proposed scheme.