AES加密过程是在一个4×4的字节矩阵上运作，这个矩阵又称为“体（state）”，其初值就是一个明文区块（矩阵中一个元素大小就是明文区块中的一个Byte）。（Rijndael加密法因支援更大的区块，其矩阵行数可视情况增加）加密时，各轮AES加密循环（除最后一轮外）均包含4个步骤：-AES encryption process is in a 4 × 4 matrix of bytes in the operation, the matrix is also known as " the body (state)" , its initial value is a plain text block (the size of the matrix is clearly an element of a Byte block .) (Rijndael encryption block for greater support, the matrix to increase the number of rows depending on the circumstances) encryption, each round of AES encryption cycle (except the last one outside) contains four steps: