A robust zero-watermarking algorithm for encrypted medical images in the DWT-DCT encrypted domain

作者：Dong Jiangtao; Li Jingbing; Duan Yucong; Guo Zhen

来源：International Journal of Simulation: Systems, Science and Technology , 2016, 17(43): 34.1-34.7.

DOI：10.5013/IJSSST.a.17.43.34

• Discrete Cosine Transform(DCT)
• DWT-DCT encrypted domain
• Feature vectors
• Homomorphic cryptosystem
• Integrity requirements
• Medical image applications
• Personal information
• Zero-watermarking

Patients’personal information contained in medical images can easily be intercepted and tampered with by unauthorized person when they are transmitted through the Internet. Therefore, it has latent risk of information leakage and should be seriously taken into account. Processing watermarking in the encrypted domain is a reasonable solution. The hybrid Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT) based watermarking method improves the robust performance of encrypted domain watermarking scheme. Due to the strict integrity requirement of medical image applications, in this paper, we propose a robust zero-watermarking algorithm in DWT-DCT encrypted domain, which does not modify the pixel value of medical images. Firstly, we scramble the original medical images by utilizing Logistic chaotic map. Then, we extract the DWT-DCT low frequency coefficients as medical images’feature vector. In watermark embedding and extraction phases, we adopt zero-watermarking technique to ensure the integrity of medical images. Taking “db2”wavelet transform for example, we conduct the experiments on the visual quality and robustness of our watermarking scheme. Experimental results demonstrate that our algorithm is not only robust against common attacks such Gaussian noise and JPEG compression, but can also withstand all levels of geometric distortions. Thus it can be effectively put into medical application.

• 出版日期2016