| |
| With the popular use of cloud computing, much attention has been paid to reversible watermarking in encryption domain. However, most existing algorithms are designed for redundant carriers, and they are difficult to resist common attacks. Furthermore, watermark can only be extracted in the plaintext domain or the ciphertext domain. In this paper, a separable robust reversible watermarking in encrypted 2D vector graphics is proposed. Firstly, a content owner uses an encryption key to scramble the polar angle of the vertices to encrypt the graphics in the polar coordinate system. After that, a watermark embedder maps the encoded watermark bits to different vertices under the control of an embedded key and a hash function, and then the polar angle of the vertex is slightly adjusted to embed a watermark. Since the decryption operation does not affect the embedded watermark, the watermark can be extracted both in the plaintext and ciphertext domain. Experimental results and analysis show that the proposed algorithm can achieve good invisibility, and it can effectively resist common operations (such as rotation, translation, scaling (RST)and entity reordering) and malicious attacks (such as the addition and deletion of vertices or entities). |
|
| Keywords:Data security; Reversible watermarking in encrypted domain; Robust reversible watermark; 2D vector graphics |
|
