A Novel Lossless Data Hiding Scheme in Homomorphically Encrypted Images

In this paper, we have presented a novel lossless data hiding scheme in a homomorphically encrypted image. After applying the homomorphic encryption function to the original image by the content owner, the data hider can embed the additional data in a lossless manner, without revealing the original content of the image. Meanwhile, the data hider chooses a threshold value and generates a location map accordingly. This location map is considered as an auxiliary information. The receiver can recover the additional data using the shared auxiliary information in a separable manner. And the original image is recovered losslessly, without any post-processing, by the homomorphic decryption function. In our proposed scheme, no distortion is introduced in the data hiding phase, as a result the directly decrypted image is the same as the original image. The experimental results show that, the scheme has better performance than some of the state-of-the-art methods with high embedding rate and distortionless directly decrypted image.