A robust VC scheme for securing cloud data storage

Abstract

Visual Cryptography (VC) was created to encode images into several shares and decode them by aggregating the shares without the use of costly standard cryptanalysis. To enhance the quality and security of visual images in cloud storage, a Robust Collusion Avoidance-based Secure Signific VC (RCA-SSVC) scheme was designed, which creates the collusion-resistance Secret Image (SI) shares and embeds them into the Cover Image (CI) to prevent collusion threats. But it takes a long-time during access for users to recover the real image whenever receiving fake shares kept in the cloud by unauthorized users. Therefore, in this article, a new 2-level data protection scheme is proposed using QR code and RCA-SSVC. In this scheme, the public and private information of users are taken as QR code, which is encoded into sub-pixel blocks of all shares during the share creation phase. Also, a random permutation is applied to the created shares to disrupt the sub-pixels in a single block, which can avoid attackers from guessing the location of the Secret QR (SQR) code’s pixels. During the image restoration step, the restoration process is initiated once the user identity is authenticated by reading QR code information, which is matched with the QR code embedded in the shares. So, image restoration using illegitimate shares during access is prevented. At last, the test outcomes reveal that the RCA-SSVC-QR establishes maximum confidentiality in image access from the cloud storage compared to the classical VC schemes.