提出了一种新的细胞自动机———二维可控细胞自动机。根据二维可控细胞自动机的性质，提出了一 种具有梯型结构的二维可控细胞自动机的伪随机序列发生方法。计算机模拟表明，具有梯型结构的二维可控细 胞自动机伪随机序列发生器实现简单，产生的序列具有速度高、统计特性好等优点。新的细胞自动机在对称密 码学中有广泛地应用。

A novel cellular automata (CA) — two-dimensional controllable CA — is proposed in this paper.  According to characteristics of two-dimensional controllable CA,  a pseudo random generating method based on two-dimensional controllable CA with a trapezoidal structure is presented.  Simulation demonstrates that pseudo random bit sequence generator based on the two-dimensional controllable CA with a trapezoidal structure is easily implemented,  and can generate high speed bit sequence and excellent statistical properties.  This novel CA is widely used in symmetrical cryptography.