AES的基本要求是，采用对称分组密码体制。AES的加密数据块长度固定为128 比特，密钥长度则可以是128，192或256比特。AES加密有很多轮的重复和变换。大致步骤如下：1、密钥扩展（KeyExpansion）。2、初始轮（Initial Round）。3、重复轮（Rounds）。每一轮由四个不同的阶段组成，包括一个混淆和三个代换：字节代换（SubBytes）、行移位（ShiftRows）、列混淆（MixColumns）、轮密钥加（AddRoundKey）。4、最终轮（Final Round）。最终轮没有列混淆。-The basic requirements of the AES symmetric block ciphers. AES encrypted data block length is fixed at a 128-bit key length can be 128, 192, or 256 bits. AES encryption and many rounds of duplication and transformation. Roughly as follows: 1, the key expansion (by KeyExpansion is). 2, the initial round (the Initial the Round). 3, repeat round (Rounds,). Each round consists of four different stages, including a confusing and three substitution: byte substitution (The SubBytes), line shift (ShiftRows,), columns confusion (The MixColumns routine), the round keys (The AddRoundKey operation). 4, the final round (Final the Round). The final round is not listed confused.