Walsh-Hadamard Transform in the Homomorphic Encrypted Domain and Its Application in Image Watermarking
Walsh-Hadamard Transform in the Homomorphic Encrypted Domain and Its Application in Image Watermarking
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DOI：
10.1007/978-3-642-36373-3_16
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发表时间：
2012-05
期刊：
影响因子：
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通讯作者：
Peijia Zheng;Jiwu Huang
中科院分区：
文献类型：
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作者：
Peijia Zheng;Jiwu Huang
如何在加密图像上嵌入和/或提取水印而不能够解密是一个具有挑战性的问题。在本文中，我们首先讨论了沃尔什-哈达玛变换（WHT）及其快速算法在加密域中的实现，由于其变换矩阵仅由整数组成，因此特别适合在加密域中的应用。然后通过修改相邻变换系数之间的关系，提出了一种基于WHT的加密域图像水印算法。由于加密技术的限制，盲目地从加密图像中提取水印并不是一件容易的事。然而，我们提出的算法在解密域和加密域都具有盲水印提取的特性。这意味着提取不需要纯图像或其加密版本。实验证明了我们提出的方法的有效性和优点。
How to embed and/or extract watermarks on encrypted images without being able to decrypt is a challenging problem. In this paper, we firstly discuss the implementation of Walsh-Hadamard transform (WHT) and its fast algorithm in the encrypted domain, which is particularly suitable for the applications in the encrypted domain for its transform matrix consists of only integers. Then by modifying the relations among the adjacent transform coefficients, we propose an WHT-based image watermarking algorithm in the encrypted domain. Due to the constrains of the encryption, extracting a watermark blindly from an encrypted image is not a easy task. However, our proposed algorithm possesses the characteristics of blind watermark extraction both in the decrypted domain and the encrypted domain. This means neither the plain image nor its encrypted version is required for the extraction. The experiments demonstrate the validity and the advantages of our proposed method.