This paper presents a multi-mode generalized modified transition chaotic map and a switched chaotic encryption scheme based on it. Eight different modes of operation can be selected based on the map graph (concave or convex), the range modification procedure (shrinking or widening) and the sign of one of its independent parameters. The generalization and modification preserve the controllability and continuous chaotic behavior properties, respectively. For the same encryption key and map equation, multi-mode operation occurs through switching between four alternatives of the dependent parameters. Switching between various modes is shown to overpass single modes in randomness by investigating the frequency distribution, autocorrelation function, histograms and 0-1 test. In addition, most bits, 75%, of the scaled and quantized chaotic output are shown to be suitable for pseudo-random number generation based on National Institute of Standards & Technology (NIST) statistical test suite. The performance of the proposed scheme is validated for several speech, grayscale and RGB images through various evaluation criteria, where good results are achieved. These criteria include basic perceptual and statistical aspects, the more advanced NIST tests, key sensitivity and robustness against brute force and differential attacks. The efficiency of the scheme is improved by up to three or six times faster than encrypting one sample or one channel of a pixel at a time for speech and image inputs, respectively. The proposed scheme demonstrates good security and efficiency with more applied evaluation criteria compared to similar recent works.

提出了一种多模式广义修正过渡混沌映射图和基于该映射的交换混沌加密方案。可以根据地图图形（凹面或凸面），范围修改过程（缩小或加宽）及其独立参数之一的符号来选择八种不同的操作模式。泛化和修改分别保留了可控性和连续混沌行为属性。对于相同的加密密钥和映射方程式，通过在从属参数的四个替代方案之间切换来进行多模式操作。通过研究频率分布，自相关函数，直方图和0-1测试，可以看出在各种模式之间进行切换可以随机超越单个模式。此外，大多数位75％基于美国国家标准技术研究院（NIST）统计测试套件，已缩放和量化的混沌输出中的一部分适合于伪随机数生成。通过各种评估标准，对几种语音，灰度和RGB图像验证了所提方案的性能，并取得了良好的效果。这些标准包括基本的感知和统计方面，更高级的NIST测试，针对蛮力和差异攻击的关键敏感性和鲁棒性。与分别为语音和图像输入一次加密一个样本或一个像素的一个通道相比，该方案的效率提高了多达三到六倍。与类似的近期工作相比，该方案证明了良好的安全性和效率，并具有更多适用的评估标准。