Research On Image Encryption Algorithm Based On Chaos Theory And DNA Sequence Coding

With the development of information technology and internet technology, People’s production and lifestyle have been changed. Through the Internet, people can transmit large amounts of information quickly and efficiently. The open system Interconnection and the defect of network protocol, which make us have to pay attention to their safety when we enjoy the convenience of the Internet age. As one of the main ways of network information, the image information security of multimedia information has been paid more and more attention. Image information is widely used in many fields, Image encryption technology is the main way to protect the secure transmission of images. So, image encryption technology has been innovated and improved constantly. For the further research of image encryption technology, design and application the more efficient and security image encryption algorithm have positive significance to the development of the image encryption technology.This paper discusses the basic knowledge of chaos theory and common model of chaotic system briefly, then introduce the DNA cryptography knowledge and the application of DNA encoding and DNA operation in image encryption field. In view of the defects of lack of ability to resist differential attack in the encryption algorithm in the present, this paper proposes a new color image encryption method based on DNA coding and hyper-chaotic system. The main research work and innovation points of this paper divided into the following aspects:This article first stated the research hotpot about knowledge of DNA computing. The relevant DNA coding applied to image encryption with the mathematical calculation complexity of hyper-chaotic system as the basis of security encryption algorithm. In order to improve the anti differential attack ability, introduced new extraction methods of auxiliary parameters. And verify its effectiveness in application. Proposed new color image encryption algorithm combined DNA sequence encoding with hyper-chaotic system and chaotic systems.Proposed two new methods for extracting auxiliary parameters form DNA sequence. The steps of a method as follows:scrambling the RGB components of true color image, encoding information, then extraction of Hamming distance between the three DNA matrices as the auxiliary parameters, auxiliary parameter decision the way of encryption template coding. Another method steps are as follows:random coding the true color image to sequence of DNA based on the pseudo random sequence generated by a chaotic system. Extract the bases ratio in the DNA sequence as the auxiliary parameters, those auxiliary parameters will be used to change the initial parameters of another chaotic system. Both methods extract parameters from the DNA sequence that on behalf of the original image information. That’s the key factors to improve the ability of resist differential attack.True color image encryption algorithm that combine DNA sequence coding and DNA sequence operation with four dimensional Lorenz chaotic system. The algorithm uses two of the four pseudo-random sequences from Lorenz map, making their sort index as the basis of image pixels scrambling. And the other two as the template that used to perform the DNA operation with scrambled image. Complete the processes that original image pixel scrambling and diffusion. This two steps using only one chaotic system map. Intersecting DNA sequence encoding and chaos sequence operation. Security of the algorithm is improved.Proposed true color image encryption algorithm based on random DNA sequence encoding and pseudo-random sequence mapping from chaotic system. In the algorithm, encoding original image and template, operation the encoded DNA sequence, DNA sequence decoded as pixel gray value, the three process all select one of eight DNA sequence operation based on Logistic chaotic map. Enhance the reliability of the encryption algorithm. Generate the encryption template from four-dimensional Chen chaotic system, Making key space further increases and the key sensitivity enhancement.These innovations are applied to the encryption algorithm. For algorithm simulation, comparison and analysis of the security of new algorithm, the results contrast proved the superiority of the algorithm proposed in this paper. The paper finally makes the summary to the full text work and outlook future research and development trend of the field of image encryption.