Speech encryption algorithm based on two newly designed chaotic maps

Abstract

Two new integrated chaotic maps are designed. The sine and logistic maps are used to create a sine-logistic integrated map (SLIM). The sine and cubic maps are used to design a sine-cubic integrated map (SCIM). Their dynamical analyses are done using time series plots, 0–1 tests, bifurcations, sample entropy, and Lyapunov exponent diagrams. The newly designed chaotic maps exhibit their dynamical properties of a period-two cycle, period-four cycle, and chaos. The speech signal is compressed first, and encryption is performed based on the new integrated chaotic maps. The two keys, such as key-A and key-B, are generated using SLIM and SCIM, respectively. Key-A is used for the shifting operation, while the bitwise XOR operation is carried out between the compressed-shifted speech signal and key-B. After that, the encrypted speech is sent across a public channel, and the original speech is recovered by performing reverse operations on the receiving end. The degree of security is measured using various speech security and attack analysis tools. It is found that the proposed strategy is more secure than some existing methods described in the literature and can withstand several attacks.

Keywords

• Bifurcation
• Chaotic map
• Compression
• Encryption
• Lyapunov exponent
• Security