Research On Design,Analysis And Application Of High-dimensional Chaotic Stream Cipher

Chaotic cryptography is an interdisciplinary subject combing chaos theory and cryptography.After nearly 30 years of research and exploration by scholars at home and abroad,some achievements have been made in the field of information security,such as image eccryption,Hash function,digital watermarking and so on.However,compared with classical cryptography,chaotic cryptography is still in its infancy and have long way to reach the maturity of practice.The related theoretical research is not yet mature,and there are few widely accepted trade or international standards.Therefore,how to design and implement a secure and efficient chaotic cryptosystem is of greatest importance and never-end race.To address this issue,this paper further studies the design,analysis and application of high-dimensional chaotic stream cipher,the main works are given as follows:1.A chaos-based two level video encryption algorithm is proposed and implemented in ARM-Embedded platform,which can be stated as follows:(1)First,an 8D discrete-time chaotic map-based system is construct,which possesses the required property of 1-1 suection in the integer range[1,N-1],suitable for position scrambling of each video frame.(2)An 8D discrete-time hyperchaotic system is designed for encryption-decryption of pixel values.(3)A complete set of video secure communication system,including transmitter side,reciver end and actual channel transimission,is implemented on ARM-Embedded platform.The experimental results and secure analysis results are also given.2.A chaotic video secure communication scheme based on multiuser is proposed and implemented in smartphone.At Transmitter sider,a joint encryption and compression scheme is designed by embedding a chaotic encryption scheme into the MJPG-steamer source codes.Then,the encrypted video data is sent to the smartphone client via WAN remote reansmission.Finally,the encrypted video data is received and decrypted in Android smartphone client.The experimental results shown that the proposed scheme can serve as a good example of chaotic secure communications for smartphone and other mobile facilties in the future.3.The approach based on message block controlled 8D hypherchaotic map is studied to construct a one-way hash function.The approach consists of three steps:(1)Two nominal matrices both with constant and variable parameters are adopted for designing 8D discrete-time hyperchaotic systems,respectively.(2)The input plaintext message block is transformed,which is used as a control matrix for the switch of the normal matrix elements both with constant and variable parameters.(3)The Hash value is calculated by the iterative outputs of hyperchaotic systems.Its secure analysis results are also given,validating the feasibility and reliability of the proposed approach.4.The security performace analysis for a self-synchronization chaotic stream cipher is investigated.According to chaosen-ciphertext attack,it is found that under the condition of selecting the ciphertext as fixed value,the orginal chaotic iterative equation is degenerated as an asumptotically stable iterative one.Based on this idea,and according to chosen-ciphertext attack,a single key decipher algorithm is proposed.Firstly,multiple pairs of plaintext-ciphertext are obtained by choosing the corresponding multiple frames of ciphertext as fixed values.Secondly,a set of possible estimated values for this single key is acquired by utilizing among one pair of plaintextciphertext.Finally,the only estimated value that satisfies all the conditions of multiple pairs of plaintext-ciphertext is determined,as an estimated value from the set of all possible estimated values.Security performance analysis results have shown that,the proposed algorithm can respectively decipher each individual key accurately.5.The cryptoanalysis for an 8D self-synchronous and feedback-based chaotic stream cipher with the low 8 bits of state variables for encryption is proposed.According to known-plaintext attack and divide-and-conquer attack,the secret keys a1i,a2i,a3i(i=1,2,…,8)are decipher by properly setting 64 different kinds of initial conditions.Then,according to chosen-ciphertext attack and divide-and-conquer attack,it is found that under the condition of selecting the ciphertext as "0",the original chaotic equation is degenerated as a linear one.So,by setting appropriate initial conditions,the secret keys a4i,a5i,a6i,a7i,a8i(i = 4,5,6,7,8)can be deciphered.Finally,an improved chaotic stream cipher scheme is proposed for improving the ability to resist divide-and-conquer attack and chosen-ciphertext attack.