An Efficient and Secure DNA based Image Encryption Technique

In this paper, an efficient and secure DNA based image encryption technique using hyper chaos Lorenz function is proposed. The technique employs SHA-512 hash of gray scale image and primary key to alter the initial seeds of hyper chaos Lorenz function. Initially, chaotic sequences are generated and redesigned. Then, an image is divided into blocks and randomly shuffled according to the primary key. Further perform circular shift operation over the rows of the shuffled image matrix and index based scrambling operation over the columns. After that, perform dynamic encoding and diffusion based DNA algebraic operation over the encoded DNA sequence and DNA based Key sequence using chaotic sequence. Finally, DNA decoding is employed to convert the diffused dynamic matrix into a ciphered image. The dynamicity of the chaotic sequences makes its extraordinary and contributes to the enhanced security and robustness of the technique. Implementation, security and performance analysis demonstrate that the technique has not only an outstanding encryption effect, but also posses large key space, less pixel correlation, low computation time and successfully resilient to the statistical, differential and brute-force attack. Comparative analysis with other references proves its efficiency and practicability for real time applications

A Naïve Visual Cryptographic Algorithm for the Transfer of Compressed Medical Images

The transmission of a suitably compressed image over a bandwidth, over long distances, gives rise towards a new era in the field of information technology. A gradual increase in this appending scenic application, involving the transfer of the images securely over the Ethernet has become an increasingly important aspect to be addressed during thou phenomenon, especially in the transfer of the digital medical images vividly, encapsulated with abundant information related to these images. The compressed medical images of the DICOM format contain certain amount of confidential data, pertaining to a clinical research or to an individual, and the confidentiality of the same has to be preserved from various security threats and eves-dropping. With a widespread applications among various multimedia applicative systems, telemedicine, medical imaging, military and certain safety-critical applications, inter-net and intra-net communicative applications, etc, a reliable transfer of suitable information, efficiently & securely is considered as one of the revolutionary aims in today’s communication technology and visual cryptographic methodologies. Real-time applications as such detailed above majorly is concerned with the security measures and many algorithms have been developed as a proof for various visual cryptographic methodologies. In this paper we propose an efficient and a reliable visual cryptographic methodology which focuses on the encryption and decryption of the two-dimensional DICOM standard compressed medical image, effectively.  This paper discusses an efficient design of 192 bit encoder using AES Rijndael Algorithm with the decomposition of an image into square image size blocks and the image blocks are shuffled using 2D CAT map. The shuffling of the image blocks/pixels employs a Logistic map of these image pixels coupled with 2D mapping of the pixels of the DICOM standard medical image, generated randomly, being the control parameter thereby creating a confusion between the cipher and the plain image, gradually increasing the resistive factor against the significant attacks. This paper proposes various analytical metrics such as correlation analysis, entropy analysis, homogeneity analysis, energy analysis, contrast and mean of absolute deviation analysis, to evaluate the proposed algorithm, and their suitability in image encryption applications