Research On Speech Encryption Algorithm Based On Chaotic System And DNA Coding

With the development of modern communication technology,speech plays an extremely important role in our daily life,so how to ensure the security of speech in the transmission process has become an imminent problem.In order to prevent the voice information from being stolen in the transmission link,the voice information can be encrypted before transmission,so that the voice information can be transmitted in the form of ciphertext.This article designs two kinds of speech encryption schemes based on chaotic system and DNA sequence.The main work is as follows:1)A speech encryption algorithm based on chaotic system and DNA coding is designed.The initial chaotic system value of the algorithm is determined by plaintext and external key,which makes the algorithm effective against selective plaintext attack.The diffusion process uses dynamic DNA coding and XOR operation to effectively enhance the diffusion effect of sample points,so that the speech information can be initially hidden.The chaos sequence is arranged in ascending order,and the speech sequence is scrambled by the scrambling process of chaos sequence,which increases the difficulty of cracking.After index scrambling encryption,the proportion of positive and negative numbers of encrypted speech is the same as that of original speech.In order to destroy the correlation between positive and negative,a method of speech polarity scrambling is proposed to randomly change the positive and negative values of speech,so that the algorithm can effectively resist statistical attack.Simulation results and performance analysis show that the algorithm has good encryption effect.2)A speech encryption algorithm based on DNA coding and cyclic shift is designed.The initial value of the 2-D Henon chaotic system of the algorithm is calculated by the string information key and the 256-bit hash value generated by SHA-256 from the original speech,which makes the encryption algorithm able to resist the selective plaintext attack effectively.Meanwhile,the string information key also increases the key space,making the key free from the number.Firstly,the encryption algorithm uses dynamic DNA encoding to carry out initial diffusion encryption of speech.Since the same coding rules may exist in the process of DNA encoding and decoding,the XOR operation is proposed to further improve the diffusion range.After the speech is diffused,the speech data is filled and the dimension transformation is carried out.In the two-dimensional space,the random chaotic sequence is used to carry out dynamic cyclic shift to enhance the scrambling effect of the encryption algorithm.Filled data also increases the clutter space of the original data.Simulation results and performance analysis show that the encryption algorithm has strong key sensitivity and large key space,and can effectively resist various attacks.