Efficient speech encryption algorithm based on three-dimensional quadratic exponential robust chaos

Abstract

The computational accuracy and parameter spacing of the existing chaos result in the gradual degradation of the chaos, which makes the sequence become periodic sequence, and the divergence rate and divergence index of the existing chaos are low. In addition, the current speech encryption algorithm has high complexity and low computational efficiency. To solve these problems, a three-dimensional quadratic exponential chaos is proposed and an efficient speech encryption algorithm is designed. To solve the problem of slow numerical divergence, the double exponential nesting structure is used and the expansion factor $beta$ is introduced to effectively reduce the number of iterations when complete chaos is reached. In order to improve the internal complexity of chaotic sequence, the whole chaotic equation is standardized, so that the generated chaotic sequence has a wide distribution. Considering that the algorithm can be stably deployed in the hardware chip in the future, and take into account the encryption rate. In this paper, the speech encryption algorithm adopts the parallel processing of confusion and diffusion, and makes the residual processing of the generated encrypted speech to improve the scrambling effect and encryption efficiency. Simulation results show that the proposed chaos equation achieves remarkable exponential divergence rate, robustness and hardware deployability. The proposed speech encryption algorithm has high efficiency, low complexity, high noise ratio, can resist a series of attacks, and has high security. This paper presents an efficient encryption strategy for speech encryption.