Video Encryption Algorithm Based On Compound Chaos

With the development of modern science and technology,Internet technology has been more and more widely used in the fields of medical,education,commerce and even national defense,especially digital image,which has gained wide attention with its visual advantages.However,every coin has its two sides.While enjoying the convenience of the Internet,people also have to face the problem of data transmission security.So,image encryption is the key technology to solve the problem.There are many similarities between chaos and cryptography,such as its sensitivity to initial values,good ergodicity and randomness of chaotic sequences,and the uncertainty of keys.The relativity of theoretical features makes them combine,which makes the encryption effect in image field better than traditional encryption methods.Therefore,chaos is widely used in security field and becomes a new direction to solve image encryption problems.This thesis designs a video encryption transmission system based on chaos.Firstly,this thesis expounds the cryptography theory and the principle of chaos,and clarifies that chaos principle,applied to the field of digital image encryption,will be widely used.However,due to the limitation of computer accuracy,the randomness of chaotic sequences will also be reduced.In order to deal with the above problems,a hybrid chaotic encryption algorithm is proposed to obtain data more quickly and safely.Firstly,because the security of single chaotic encryption system is not high and the key space is not large,this thesis designs an image encryption algorithm based on the mixture of 1D chaos and 3D chaos.Two sets of Logistic chaotic sequences are iterated,and the results are used to replace the pixels and obtain the initial values of Bao system.Two sets of Logistic chaotic sequences are iterated,and the results are used to replace the pixels.At the same time,the initial values of Bao system are obtained.Then the chaotic sequence for substitution and diffusion is obtained by using plaintext pixel value and Bao system.Finally,the plaintext image is encrypted and decrypted by using the decryption formula.Hybrid chaotic encryption algorithm enhances the randomness of chaotic sequence,increases the key space,improves the security of encryption system,and improves the performance of the above algorithm.Secondly,because hyperchaos has the advantage of complex dynamic characteristics,and in order to ensure the encryption rate,a hybrid algorithm of 2D hyperchaos and 3D chaos is proposed to encrypt images.The main function of chaotic sequence generated by Kawakami hyperchaotic system is permutation.Permutation introduces the form that the current pixel exchanges only with the pixel after its position,so that only one round of permutation can produce good results.At the same time,using linear feedback shift register and byte reorganization,the initial value of 3D Lv system is dynamically generated,and byte substitution is used to make the design of encryption parameters more complex.Finally,the encryption and decryption tests of the transmission are completed on two computers,and the algorithm has strong anti-attack ability and fast encryption rate.