A high-capacity image reversible data hiding method in ciphertext domain

Abstract

The invention discloses a ciphertext domain high-capacity image reversible data hiding method, including prediction error detection, image encryption, ciphertext domain image reversible data hiding, secret information extraction and original image non-destructive recovery, wherein in the first part, all pixel points in a grayscale image are first divided into two categories that are sampling pixelpoints and non-sampling pixel points, and then all non-sampling pixel points are marked as prediction errors and accurate predictions respectively; in the second part, the marked grayscale image is encrypted by using a binary pseudo-random sequence generated by an encryption key; in the third part, the secret information is encrypted by using a binary pseudo-random sequence generated by a data hiding key, and then the encrypted secret information is used to embed data into each non-sampling pixel point that is marked as the accurate prediction in a ciphertext domain image; and in the fourth part, only the secret information is extracted, or only the original grayscale image is recovered, or the secret information is extracted first and then the original grayscale image is recovered. The method has the advantages that information can be embedded in the ciphertext domain image, and the embedding capacity is high.

Description

technical field [0001] The invention relates to a data hiding technology, in particular to a method for reversible data hiding of a high-capacity image in a ciphertext domain. Background technique [0002] Under the cloud computing platform, the provider of multimedia content does not have to be a storer and a processor at the same time. In this mode of work, user data is largely "out of control". One of the best ways to ensure the security of multimedia data is to encrypt the multimedia data. Users first encrypt sensitive content before uploading. All processing and calculations in the cloud are performed in the ciphertext domain, and the processing results are provided to the user. The user can only obtain the plaintext data after decryption. [0003] In many application scenarios, some cloud service managers who do not have decryption authority need to embed some additional information in the encrypted carrier, such as annotation or authentication data, work source info...

AI Technical Summary

Problems solved by technology

The existing encryption domain reversible data hiding technology can be divided into three categories: the first category is to encrypt the image and then find the data embedding space, this kind of method generally has a low embedding capacity, and data extraction errors will occur; the second category is the image The data embedding space is reserved before encryption. This type of method has a large embedding capacity and low distortion, but the disadvantage is that a complex protocol is required between the image encryptor and the data embedder; the third type is to use homomorphic encryption to realize reversible image data in the ciphertext domain Hidden, but homomorphic encryption can easily cause ciphertext data expansion

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