Research Of Voice Security Algorithm Based On Confidential Phone Fusing Chaotic Sequence With AES

Voice communication is an important means of daily communication and exchange, the problem on security of voice communication has become widespread concerned in today’s society. Voice communication security concerns all aspects of social life, and therefore, it has important practical significance to develop efficient algorithms for voice security and secure communications.AES algorithm represents the most advanced encryption technology,which is also most widely used. With rigorous mathematical theory supporting and overall framework of advanced design, so it can withstand attacks from differential and linear crypt-analysis. However, the square attacks and power analysis methods have been successfully cracked a small number of rounds AES. The trajectories of chaotic system is difficult to predict and can produce huge output by tiny input difference,and cryptography is closely linked. The defects of original AES algorithm can be solved by fusion of chaotic sequences.Based on research at home and abroad, from the basic principles and security of AES, chaos theory, the fusion of chaotic sequences and AES algorithm is studied in detail in the paper and an improved chaotic AES algorithm has been designed. The following work has been done in this thesis:Firstly, an algorithm on generation of chaotic key streams has been designed. Due to the security risk of the key extension part is public for original algorithms and sub-key that can be derived from each other, the improved algorithm preserves the frame of the original AES, uses the characteristics of high-dimensional chaotic system can generate highly unpredictable random sequences, extracting dynamic encryption key streams which generated by Lorenz system and Chen system XOR, to replace the original key streams. Compared to the original key expansion algorithm, the new algorithm for key generation occupies small storage space, easily to be implemented and the randomness of the generated keystreams is also good, so the algorithm can improve the encryption efficiency.Secondly, a method to further improve the randomness of key sequences is designed, and the iterative rounds of the AES encryption is simplified. On the basis of analyzing the process of chaotic key sequences in detail,the method of extracting the encryption key streams dynamically from the pre-processed chaotic mixing sequences is proposed;simplifying the iterative rounds of AES to six, which not only guarantees the strength of the algorithm, but also greatly improves the speed of encryption and decryption. Through simulation results shows that the improved algorithm is superior to other encryption algorithms.Testing the improved chaotic AES algorithm by MATLAB and the simulation results are analyzed, the new encryption algorithm is validated feasible, and by analyzing from several aspects, show that the new algorithm has certain advantages on security and efficiency of encryption than others.