In this paper, we design, realize and evaluate a new secure cryptosystem based on a Pseudo-Chaotic Number Generator(PCNG), a global diffusion and a block cipher in Cipher Block Chaining(CBC) mode. The proposed PCNG, defined over a finite field, is based on a discrete Chebyshev map coupled with a Pseudo-Random Number Generator(PRNG) and a discrete skew tent map. Our PCNG can remove a hidden danger of deteriorated security caused by the dynamical degradation encountered in numerical implementation of chaotic maps defined on real numbers. The global diffusion uses a Horizontal Addition Diffusion(HAD) and a Vertical Addition Diffusion(VAD) followed by a modified 2-D cat map. The block cipher in CBC mode is based on a confusion layer using the AES S-Box, followed by a diffusion layer built on the modified 2-D cat map and a key addition operation. The global diffusion enhances the diffusion process of the block cipher. Conducted security analysis and the obtained results have proven that the proposed cryptosystem design is robust with high security and that it can be applied to practical implementations.

在本文中，我们设计，实现和评估了一种基于伪混沌数发生器（PCNG），全局扩散和密码块链（CBC）模式下的分组密码的新型安全密码系统。在有限域上定义的拟议PCNG基于离散Chebyshev映射，伪随机数生成器（PRNG）和离散偏斜帐篷图。我们的PCNG可以消除因在实数上定义的混沌图的数字实现中遇到的动态退化而导致的安全性下降的隐患。全局扩散使用水平加法扩散（HAD）和垂直加法扩散（VAD），然后使用修改后的二维猫图。CBC模式下的分组密码基于使用AES S-Box的混淆层，然后是基于修改后的二维猫图和密钥添加操作构建的扩散层。全局扩散增强了分组密码的扩散过程。进行的安全性分析和所获得的结果证明，所提出的密码系统设计具有较高的安全性，并且具有鲁棒性，并且可以应用于实际实施中。