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Digital image plays an important role of information carrier with the rapid development of information technology. In this paper, a compressible image encryption method based on nondegenerate hyperchaos is proposed. Firstly, a nondegenerate hyperchaotic system based on the nonlinear feedback controller is designed, and its dynamic characteristic is analyzed. The image information is compressed by integer discrete cosine transform (DCT). Then the image encryption algorithm is proposed by using the pseudo‐random sequence generated by hyperchaotic system. Finally, the proposed scheme is realized by using ZYNQ development platform. The security of proposed scheme is enhanced by the nondegenerate hyperchaotic system, and the data volume for encryption algorithm is reduced by DCT preprocessing without affecting the image visual quality. The hardware implementation based on ZYNQ platform shows the feasibility of the proposed scheme. Through the security analysis of the experimental results, it is verified that the image can be well encrypted by the proposed method with great performance. [ABSTRACT FROM AUTHOR]

Summary: In the paper, a novel six‐dimensional hyperchaotic system is proposed for secure communication. A detailed analysis of some relevant features, such as equilibrium stability, dissipation, bifurcation, and Lyapunov exponents. The results show that there are hyperchaos, chaos, quasi‐periodic, and periodic dynamic behaviors for our constructed hyperchaotic system. Then the six‐dimensional hyperchaotic system is simulated and implemented, which verified its physical realizability. The six‐dimensional hyperchaotic system is applied to complete the signal encryption and decryption circuit design, then the circuit is tested. The results indicate that the proposed hyperchaotic system can play an important role in some key areas such as communication security and complex systems. [ABSTRACT FROM AUTHOR]

Summary: Based on an existing 4‐dimensional Lorenz hyperchaotic system, a novel 5‐dimensional hyperchaotic system is proposed by an extra linear control coefficient in this paper. Some related characters are analysed comprehensively, including the stability of equilibrium, dissipativity, rotation symmetry, bifurcations, Lyapunov exponent, and Poincare surface of a section of the hyperchaotic system. The 5‐dimensional hyperchaotic system is then implemented and simulated in the circuit simulation software NI Multisim. The results indicate that the proposed hyperchaotic system exhibits hyperchaos, chaos, and quasi‐periodic and periodic dynamic behaviours, which can facilitate and enhance the security of chaos‐based communication. [ABSTRACT FROM AUTHOR]