A new 1D chaotic system for image encryption

Scalable secret image sharing (SSIS) is a new secret image sharing technique. The feature of scalability refers to the fact that the revealed secret information is proportional to the number of gathered shadows. Once all of the valid shadows are collected, the complete secret can be revealed easily. The kernel of secret information, however, may be leaked out with a few shadows collected in the existing SSIS mechanisms. This is because researchers seldom concerned about secret distribution. Thus, we introduce the Salient map to develop a new method, in which the ROIs (region of interesting) of secret image can be revealed progressively. Additionally, we introduce the concepts of meaningful shadow and verification to SSIS. To the best of our knowledge, this is the first SSIS that employs a meaningful shadow. The leading adoption can greatly help reduce the attention of attackers in order to enhance the security, while the second concept can avoid malicious behaviors from outside attackers or dishonest members.

Selective scalable secret image sharing with verification

Proceedings of world academy of science, engineering and technology, vol 8

Image encryption by random grids

A DNA-based color image encryption method is proposed by using three 1D chaotic systems with excellent performance and easy implementation.The key streams used for encryption are related to both the secret keys and the plain-image.To improve the security and sensitivity, a division-shuffling process is introduced.Transforming the plain-image and the key streams into the DNA matrices randomly can further enhance the security of the cryptosystem.The presented scheme has a good robustness for some common image processing operations and geometric attack. This paper proposes a new encryption scheme for color images based on Deoxyribonucleic acid (DNA) sequence operations and multiple improved one-dimensional (1D) chaotic systems with excellent performance. Firstly, the key streams are generated from three improved 1D chaotic systems by using the secret keys and the plain-image. Transform randomly the key streams and the plain-image into the DNA matrices by the DNA encoding rules, respectively. Secondly, perform the DNA complementary and XOR operations on the DNA matrices to get the scrambled DNA matrices. Thirdly, decompose equally the scrambled DNA matrices into blocks and shuffle these blocks randomly. Finally, implement the DNA XOR and addition operations on the DNA matrices obtained from the previous step and the key streams, and then convert the encrypted DNA matrices into the cipher-image by the DNA decoding rules. Experimental results and security analysis show that the proposed encryption scheme has a good encryption effect and high security. Moreover, it has a strong robustness for the common image processing operations and geometric attack.

A new color image encryption scheme based on DNA sequences and multiple improved 1D chaotic maps

Visual cryptography for color images

The basic (k, n)-threshold visual cryptography (VC) scheme is to share a secret image with n participants. The secret image can be recovered while stacking k or more shares obtained; but we will get nothing if there are less than k pieces of shares being overlapped. On the contrary, progressive VC can be utilized to recover the secret image gradually by superimposing more and more shares. If we only have a few pieces of shares, we could get an outline of the secret image; by increasing the number of the shares being stacked, the details of the hidden information can be revealed progressively. Previous research, such as Jin in 2005, and Fang and Lin in 2006, were all based upon pixel-expansion, which not only causes the waste of storage space and transmission time but also gets a poor visual quality on the stacked image. Furthermore, Fang and Lin's research had a severe security problem that will disclose the secret information on each share. In this letter, we proposed a brand new sharing scheme of progressive VC to produce pixel-unexpanded shares. In our research, the possibility for either black or white pixels of the secret image to appear as black pixels on the shares is the same, which approximates to 1/n. Therefore, no one can obtain any hidden information from a single share, hence ensures the security. When superimposing k (sheets of share), the possibility for the white pixels being stacked into black pixels remains 1/n, while the possibility rises to k/n for the black pixels, which sharpens the contrast of the stacked image and the hidden information, therefore, become more and more obvious. After superimposing all of the shares, the contrast rises to (n-1)/n which is apparently better than the traditional ways that can only obtain 50% of contrast, consequently, a clearer recovered image can be achieved.

Progressive Visual Cryptography With Unexpanded Shares

Block-based progressive visual secret sharing

A novel copyright protection scheme for digital images based on visual cryptography and statistics is proposed. The proposed method employs sampling distribution of means and visual cryptography to achieve the requirements of robustness and security. Our method can register multiple secret images without altering the host image and can identify the rightful ownership without resorting to the original image. Moreover, the proposed method enables the secret images to be of any size regardless of the size of the host image. Finally, experimental re- sults show that the proposed scheme can resist several common attacks. © 2005 Society of Photo-Optical Instrumentation Engineers.

Copyright protection scheme for digital images using visual cryptography and sampling methods

Digital watermarking is a very active research area for copyright protection of electronic documents and media. A visual cryptographic approach is used to generate two random shares of a watermark: one is embedded into the cover-image and another is kept as a secret key for the later watermark extraction. The watermark can be extracted by simply superimposing the key share over the stego-image. This asymmetric digital watermark is specially designed and is not easily changed or removed. But, it is very convenient to be extracted. The embedded digital watermark by this approach seems robust after several attacks are performed on the stego-image.

Young-Chang Hou

Papers

Visual cryptography for color images

Progressive Visual Cryptography With Unexpanded Shares

Block-based progressive visual secret sharing

Copyright protection scheme for digital images using visual cryptography and sampling methods

An asymmetric watermarking scheme based on visual cryptography