Multi-bit plane reversible data hiding method for encrypted image with small cloud storage overhead

Abstract

The invention provides a multi-bit plane reversible data hiding method for an encrypted image with small cloud storage overhead. The operation is mainly that difference images are obtained by using apixel difference prediction method, the difference images are classified by bit, and information is embedded in a manner of replacing variable bits; the operation of embedding the information is independent of the positions of pixels, so that an image XOR scrambling or a DES encryption operation can be used for the encrypted image, which improves the security of the encrypted image; the pixel difference prediction method effectively compresses an original image, so that a large amount of space is generated by high planes of a part of pixels, and a proper threshold range is found adaptively; abit plane embedding method is adopted for variable pixels within the threshold value, so that multi-bit information can be embedded into one pixel; a sparse matrix compression algorithm is used to compress a pixel classification matrix, which effectively improves the steganographic capacity; and the encrypted image of the corresponding size is generated according to the user's requirements, whichsaves the user's cloud storage overhead and expands the application range of the algorithm.

Description

technical field [0001] The invention relates to a method for reversible information hiding in an image encryption domain. Background technique [0002] With the development of network and cloud services, it is difficult for digital image data to be stored in the cloud in clear text to meet the privacy protection needs of users. Therefore, uploading encrypted versions of digital image data has become an effective means of user privacy protection; on the other hand, cloud Service providers need to hide additional information in encrypted digital images to facilitate the management of ciphertext digital images. Taking into account the needs of user privacy protection and ciphertext image management, image encryption domain reversible data hiding (RDH-EI: Reversible Data Hiding in Encrypted Image) technology has attracted more and more attention. [0003] At the receiving end, according to actual needs, legal information extractors can extract additional information from the ci...

AI Technical Summary

Problems solved by technology

[0006] In 2016, Document 1 (D. Xu, R. Wang. Separable and error-free reversible data hiding in encrypted images [J]. Signal Process., 2016, 123:9-21) proposed a pre-encryption prediction based on prediction error Space-saving RDH-EI algorithm; the information embedding of the algorithm in Document 1 uses histogram translation and difference expansion technology, this method can only embed 1 bit of information per pixel, and the maximum embedding capacity is 0.75bpp; but this algorithm encrypts images with information Risk of leakage (the encrypted image leaks part of the contour information of the original image)

[0008] With the RDH-EI algorithm applied to cloud storage scenarios, users often hope that the encrypted image files should be as small as possible when uploading, storing, and downloading. This will not only improve the efficiency of image uploading and downloading, but also save users’ cloud storage costs. ; None of the above-mentioned documents takes into account the space occupied by encrypted images in cloud storage scenarios; some researchers currently propose JPEG compression for images, but this compression method is lossy compression, and the images cannot be completely lossless. It is difficult to meet the application of specific scenarios, such as medical, military and judicial fields; how to reduce the file size of encrypted images and restore them without loss while ensuring high embedding capacity and security is an urgent need for RDH-EI technology need

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