Rijndael加密算法是分组长度可变的分组密码。分组长度，密钥长度可以为128，192，256比特。

假设加密的中间结果为状态State。状态State可以用类似于元素为一字节的矩阵来表示，矩阵的行数为4，列数为Nb，Nb等于分组长度除以32。

-Rijndael encryption algorithm is the grouping variable length block cipher. Packet length, key length for the bit 128,192,256. The assumption that an encrypted intermediate results for the state of State. State status is similar to the elements can be used as a matrix of bytes expressed as the number of rows for the matrix 4, the number of rows for the Nb, Nb equal to packet length divided by 32.