Research On Image Encryption Algorithm Based On Chaos Theory And DNA Encoding

With the development of computer and network communication technology,information storage and transmission become very convenient,information interaction become more frequent,and a large number of multimedia data dissemination in the network.Due to the openness transmission environment,information suffer the illegal theft and tampering by criminals,so information security is a serious threat.The most effective way to protect the image information security is to encrypt and hide the image information.The common and typical encryption operation mode is chaotic encryption,but there are some deficiencies.The low dimensional chaotic mapping,the system parameters and initial value are few,can not resist the exhaustive attack,and it takes a lot of time to use hyper-chaotic system for several rounds scrambling and diffusion,the efficiency is greatly reduced,at the same time the choice of plain-text attack and choose cipher-text attack ability is poor.Therefore,simply rely on chaotic system can not achieve a safe and efficient encryption effect,in order to ensure information security,combined the DNA cipher theory to design more excellent encryption algorithm.To make full use of DNA inherent high storage density,high parallelism,ultra-low energy consumption and good anti attack effect,the image information containing large amount of data is stored and encrypted,which accords with the demand of digital information development in the future,and has good application prospect in cryptography field.The encryption algorithm based on the combination of chaos and DNA encoding are studied,and mainly carried out the following research work:(1)The basic theory and knowledge of encryption and the theory of DNA cryptography are studied.On the basis,the design method of chaotic image encryption algorithm is given,basic encryption principle.It is found that image encryption algorithm relies on chaos theory has some deficiencies through in-depth study and analysis.Combining with the current research hotspot of image encryption and to solve the problem of chaotic image encryption algorithm,a color image and a two-image encryption algorithm are designed.(2)Simply rely on chaotic system can not achieve a safe and efficient encryption effect,in order to ensure information security,combined with DNA encoding theory to design a more excellent encryption algorithm.A color image encryption algorithm based on chaotic system and dynamic DNA encoding is designed.Because the DNA encoding and logic operation mode is limited,only in this way to encrypt can not achieve the desired effect,so with the aid of chaos theory,make the encryption operation more flexible and achieve image encryption security.A color image is separated by channel and single channel is decomposed to the bit plane respectively,and then select one of the channels and chaotic sequences to determine the DNA encoding and operation mode of the merging bit plane with the remaining channel,encoding and operation dynamic change,one of the channels as key and separate encryption,achieve the effect of double encryption,improve the security of the algorithm.The key varies with the plain-text,increase the correlation between the key and the plain-text.(3)Based on the above research results,a further study of double-image cross encryption algorithm based on chaotic system and DNA dynamic encoding operation.The algorithm through random sequence dynamic control the mode of DNA encoding and logic operation to complete the encryption of two images simultaneously,improve the efficiency of image encryption;secondly,the two-image information cross hybrid encoding throughout the encryption process,the final two images of cipher-text contain the information with each other,the attacker to obtain effective information more difficult,improves the ability to resist chosen plain-text,known plain-text and exhaustive attack;At the same time,the generation of chaotic sequence is closely related to the plain-text,so it enhances the correlation between key and the plain-text.By using chaos theory and DNA dynamic encoding,a color image encryption algorithm is designed,and achieved good encryption effect.On the basis,a double image encryption algorithm is designed.The simulation shows that all of them have good encryption performance and have certain practical application value and theoretical research significance.