The Algorithm Research Of Reversible Information Hiding In Cipher Domain Based On Homomorphic Encryption Scheme

With the science technology and IT technology rapid development and wide application,the limitation of traditional in time domain and airspace domain has been changed. However, with the rapid, efficient, social and international characteristics of IT technology, it has brought about the reality of resource security issues in the exchange of data. Encryption mechanism and information hiding technology from different dimensions play a role in protecting the information security, so it is often used in combination of the two. However, in some special occasions such as high requirements: military field, medical field, multimedia data is not allowed to have any change, so reversible information hiding technique in encryption domain is developed. However, the embedding capacity, the security of the original carrier and the information of the watermark non reversible are all the problems in the information hiding technology field. Therefore, to ensure the security of the original carrier content under the premise of ensuring the embedded capacity, implementation the information reversible and the original carrier free recovery in the encrypted domain for information hiding technology has great significance.In this dissertation, the research work mainly includes the following:(1) Studied the relevant knowledge of reversible information hiding technology, the background and significance of the application is explained in the domestic and foreign. The classical algorithm of reversible information hiding is analyzed and classified, and its advantages and disadvantages are summarized.(2) An efficient reversible watermarking algorithm based on predictive difference expansion is proposed for the low capacity in the reversible hiding technology of the plaintext domain. The method will be divided pixels in blocks, every block with 7 pixels, 7 pixels are divided in five small blocks and used predict difference expansion to the embedding of watermark information, get 10 prediction errors, make full use of the difference errors and get increase the embedding capacity. The experimental results show that the proposed method not only improves the embedding capacity, but also realizes the reversibility of the watermark information and non distortion recovery of the original image.(3) In the encrypted domain, under the protection of the original carrier content Security, implementation watermark reversibility and the complete restoration of the original carrier image, we proposed the reversible data hiding in encryption domain based on homomorphic mechanism. In this method, the idea of the combination of the diamond prediction scheme, the encryption mechanism and the difference histogram are introduced. The algorithm performance is improved. Experimental results show that the proposed method can achieve the reversibility of watermark information and the original image lossless restoration in the encrypted domain.