密码学中的高级加密标准（Advanced Encryption Standard，AES），又称Rijndael加密法，是美国联邦*采用的一种区块加密标准。这个标准用来替代原先的DES，已经被多方分析且广为全世界所使用。
AES加密代码
/// <summary>
/// AES加密
/// </summary>
/// <param name="encryptStr">明文</param>
/// <param name="key">密钥</param>
/// <returns></returns>
public static string Encrypt(string encryptStr,string key)
{
byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(encryptStr);
RijndaelManaged rDel = new RijndaelManaged();
rDel.Key = keyArray;
rDel.Mode = CipherMode.ECB;
rDel.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = rDel.CreateEncryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
AES解密代码
/// <summary>
/// AES解密
/// </summary>
/// <param name="decryptStr">密文</param>
/// <param name="key">密钥</param>
/// <returns></returns>
public static string Decrypt(string decryptStr,string key)
{
byte[] keyArray = UTF8Encoding.UTF8.GetBytes(key);
byte[] toEncryptArray = Convert.FromBase64String(decryptStr);
RijndaelManaged rDel = new RijndaelManaged();
rDel.Key = keyArray;
rDel.Mode = CipherMode.ECB;
rDel.Padding = PaddingMode.PKCS7;
ICryptoTransform cTransform = rDel.CreateDecryptor();
byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
return UTF8Encoding.UTF8.GetString(resultArray);
}主程序入口，测试代码
static void Main(string[] args)
{
string encryptStr,decryptStr, key;
key = "ae125efkk4454eeff444ferfkny6oxi8";
encryptStr = "C#AES加密字符串";
Console.WriteLine("============== 256位AES加密 ============\n");
Console.WriteLine("加密前的字符串："+encryptStr);
Console.WriteLine("密钥：" + key);
Console.WriteLine();
decryptStr = Program.Encrypt(encryptStr,key);
Console.WriteLine("加密后的字符串：" + decryptStr);
encryptStr = Program.Decrypt(decryptStr, key);
Console.WriteLine("解密后的字符串：" + encryptStr);
Console.ReadKey();
}