Based on the Feistel network and dynamic deoxyribonucleic acid (DNA) encoding technology, an image encryption method is proposed using the “permutation-diffusion-scrambling” structure. First, the SHA-3 algorithm is used to calculate the hash value of the plaintext image as the initial value of the hyperchaotic system, and the chaos-generated sequence is used to generate the Hill cipher matrix to replace the image pixel. Second, the DNA sequence operation is used as the F function of the Feistel network. The DNA sequence database is used as the key K of Feistel network, and the image pixel value diffusion is realized by the Feistel network. Finally, further diffusion is carried out through the ciphertext feedback and through the ciphertext confusion and diffusion of three rounds of “chaotic scrambling-DNA encoding-Feistel transformation-DNA decoding,” making the ciphertext more random and resistant to attacks and ensuring that the encrypted ciphertext is more secure. The experimental results show that the proposed method can effectively encrypt the image and has prominent characteristics, such as strong plaintext sensitivity, a large key space, and excellent ciphertext statistical properties.

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An Image Encryption Method Based on the Feistel Network and Dynamic DNA Encoding

This paper presents a novel secure medical image transmission scheme using hybrid visual cryptography and Hill cipher (HVCHC) between sender and receiver. The gray scale medical images have been considered as a secret image and split into different shares by visual cryptography (VC) encryption process. The split shares are once again encoded by Hill cipher (HC) encode process for improving the efficiency of the proposed method. In this process, the encrypted medical image (shares) pixels are converted as characters based on the character determination (CD) and lookup tables. In result, a secret image is converted into characters. These characters are sent to the receiver/authenticated person for the reconstruction process. In receiver side, the ciphertext has been decoded by HC decode process for reconstructing the shares. The reconstructed shares are decrypted by the VC decryption process for retaining the original secret medical image. The proposed algorithm has provided better CC, less execution time, higher confidentiality, integrity, and authentication (CIA). Therefore, using this proposed method, cent percent of the original secret medical image can be obtained and the secret image can be prevented from the interception of intruders/third parties.

/pdf/a-new-secure-transmission-scheme-between-senders-and-4r5waakvc6.pdf

A new secure transmission scheme between senders and receivers using HVCHC without any loss

This article suggests a new image encryption algorithm based on a secure variant of Hill Cipher (HC) and three improved one-dimensional (1D) chaotic maps. The proposed scheme fully satisfies the two basic concepts of security, namely confusion and diffusion. The confusion is ensured by the product of a vector consisting of the key-pixel couple and a 2 × 2 Hill matrix on the one hand, and the addition of another pseudo-random translation vector on the other hand. And the diffusion is ensured by a strong avalanche effect that links each encrypted pixel to its adjacent. The chaotic sequences used come from 1D chaotic maps with excellent statistical proprieties. The proposed algorithm aims to encrypt pixel-by-pixel all types of images, even those with a high correlation of adjacent pixels or a black background, and to make the encryption system more secure. So, the simulation results performed on a database of color and grayscale images show that the histogram of a cipher image produced a uniform distribution, a higher entropy, a correlation among image pixels that was significantly decreased; Also, the proposed algorithm has great performance in terms of sensitivity, UACI and NPCR.

Image encryption scheme based on a new secure variant of Hill cipher and 1D chaotic maps

The conventional Hill cipher provides less information security due to fixed N N  key matrix dimensions. In this paper, a new modified Hill cipher is introduced which provides enhanced security performance than the conventional hill cipher scheme. This enhanced security of the modified Hill cipher is dependent on the non-square N M  matrix approach. The N M  Hill cipher matrix defuses N plaintext information letters into M cipher text messages. Therefore, the varying M redundant cipher text bestowed more confusion than the conventional Hill cipher. Moreover, the modified technique provides always non-singular matrix while finding its inverse which makes free from the complication of singular matrixes in the conventional Hill cipher scheme.

/pdf/security-enhancement-of-hill-cipher-by-using-non-square-3rikbsrj9d.pdf

Security enhancement of hill cipher by using non-square matrix approach

Imaging security and biometrics are two heavily connected areas. The quick evolution of biometrics has raised the need of securing biometric data. A majority of this data is visual, which has lead to intensive development of image security techniques for biometric applications. In this paper we give a fast fly over image security approaches and imaging-related biometrics. We present the current state-of-the-art of the interplay between both areas. The emphasis in this paper is the computational methods.

http://www.ehu.eus/ccwintco/uploads/7/70/Hais_survey_03-11-2011.pdf

Vinay Kumar Minz

Papers

Privacy protection of biometric traits using modified hill cipher with involutory key and robust cryptosystem