新型忆阻器混沌电路及其在图像加密中的应用

忆阻器是一种拥有记忆功能的电阻，目前忆阻器的研究热点及难点在于新模型的建立以及相关方面的应用。该文提出一种基于双曲正弦函数的新型磁控忆阻器模型，通过分析电压和电流的相轨迹关系，发现其具有典型的忆阻器电压-电流特性曲线。利用新建的忆阻器模型构造新型忆阻混沌系统，通过数值仿真绘出新系统的相轨迹图、分岔图、Lyapunov 指数谱等，分析了不同参数时系统的混沌演化过程。另外，基于电路仿真软件Multisim研制了实验仿真电路, 该电路结构简单、易于实际制作，且仿真实验与理论分析结论十分吻合，证实了提出的忆阻混沌系统电路在物理上是可以实现的。最后，利用新系统混沌序列对图像进行加密，重点分析了加密直方图、相邻像素相关性以及抗攻击能力与密钥敏感性，结果表明新系统对图像密钥及明文都非常敏感，密钥空间较大，新提出的忆阻混沌系统应用于图像加密具有较高的安全性能。

New Memristor Chaotic Circuit and Its Application to Image Encryption

Memristor is a kind of resistance and in possession of the function of memory. The research hotspots and difficulties at present memristor lie in the application of the new model and related areas. A novel magnetron memristor model based on hyperbolic sine function is designed and found that its characteristic is consistent with the typical memristor from the trajectory of voltage and current phase. A new memristor chaotic systemshe using the new memristor model is also presented, and then the phase trajectories, the bifurcation diagram and Lyapunov exponent spectrum of the new system are plotted through numerical simulations. In addition, based on Multisim circuit simulation software for the new system simulation, both experimental and simulation results validate the proposed equivalent circuit realization. Finally, the chaotic sequences generated by the new system are used for scrambling the pixel position to protect image information security. The correlation and statistic histogram entropy of adjacent pixels, anti-attack capability and key sensitivity of the encrypted image are analyzed, which indicate that the new memristive chaotic system has much better potential advantages than other existing chaotic system in image encryption application with high safety performance.