Tang Dan

Image Encryption Based on Bivariate Polynomials

Encryption of image is different from that of texts due to some intrinsic features of images: large amount of data, highly redundancy, strong correlation among pixels and so on. Therefore, the encryption result is not very well if we used the traditional encryption methods to encrypt images. The paper proposes a new method of image encryption based on bivariate polynomials; another image is used as the key in which method. Because the size of the image key could be much smaller than the secret image, we can hold it expediently. And the method can expand to the video encryption field, and has a good perspective.

Secret Image Sharing Based on Array Codes

A new secret image sharing scheme is proposed in this paper, and which scheme is based on array codes. Any type digital images can be shared by the new method, and compared to other secret image sharing schemes, all the calculations of the new scheme only uses XOR operations, so it is very efficiently. And more, the new scheme can share multi secret images, all shadow images can have clear visual significance, and pixels of all images including secret images and shadow images would not be expanded. In addition, the new method can extend to audio and video areas easily, so we think this method will have a good perspective.

An Efficient Copyright Protection Technique for Digital Images Based on Finite Groups

It is well known that a digital signature scheme and digital timestamp are two well-defined security methods for copyright protection. However, these techniques are not suitable for dealing with digital images directly because of some intrinsic features of digital images such as large amount of data, highly redundancy, and strong correlation among pixels. For this reason, digital watermarking has received considerable attention for copyright protection. In this paper, a robust copyright protection scheme for digital image is proposed. In the new scheme, Color images can be used as the watermark is an important characteristic and the watermark does not require to be embedded into the protected image but is used to generate a secret image by addition operations over finite groups, then the secret image is registered to certified authority (CA) for further protection. The experimental results show that the proposed scheme not only can clearly verify the copyright of the digital image, but also is robust to withstand many image processing attacks.