public class AESHelper
    {
        /// <summary>
        /// 獲取密鑰
        /// </summary>
        private static string IDKey
        {
            get
            {
                return "3vZ8rRLUME4b3K8xXovptGodOUXSCjrc";
            }
        }

        private static string nameKey
        {

            
 
get
            {
                return "1a54CRZ7WdwGYdNPonWkSMtHyRhlnv6q"; 
            }
        }

        //默認密鑰向量
        private static byte[] _key1 = { 0x7f, 0x0a, 0x2d, 0x96, 0x94, 0xa5, 0xc2, 0x7b, 0xaa, 0x89, 0x00, 0x8b, 0xf3, 0xab, 0x15, 0xfd };
      /// <summary>
        /// AES加密算法
        /// </summary>
 

        /// <param name="plainText">明文字符串</param>
        /// <returns>將加密後的密文轉換為Base64編碼，以便顯示</returns>
        public static string AESEncryptID(string plainText)
        {
            //分組加密算法
            SymmetricAlgorithm aes = Rijndael.Create();
            byte[] inputByteArray = Encoding.UTF8.GetBytes(plainText);//
 
得到需要加密的字節數組
            //設置密鑰及密鑰向量
            aes.Key = Encoding.UTF8.GetBytes(IDKey);
            aes.IV = _key1;
            byte[] cipherBytes = null;
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    cipherBytes = ms.ToArray();//得到加密後的字節數組
                    cs.Close();
                    ms.Close();
                }
            }
            return Convert.ToBase64String(cipherBytes);
        }

        public static string AESEncryptName(string plainText)
        {
            //分組加密算法
            SymmetricAlgorithm aes = Rijndael.Create();
            byte[] inputByteArray = Encoding.UTF8.GetBytes(plainText);//得到需要加密的字節數組
            //設置密鑰及密鑰向量
            aes.Key = Encoding.UTF8.GetBytes(nameKey);
            aes.IV = _key1;
            byte[] cipherBytes = null;
            using (MemoryStream ms = new MemoryStream())
            {
                using (CryptoStream cs = new CryptoStream(ms, aes.CreateEncryptor(), CryptoStreamMode.Write))
                {
                    cs.Write(inputByteArray, 0, inputByteArray.Length);
                    cs.FlushFinalBlock();
                    cipherBytes = ms.ToArray();//得到加密後的字節數組
                    cs.Close();
                    ms.Close();
                }
            }
            return Convert.ToBase64String(cipherBytes);
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="cipherText">密文字符串</param>
        /// <returns>返回解密後的明文字符串</returns>
        public static string AESDecryptId(string showText)
        {
            byte[] cipherText = Convert.FromBase64String(showText);

            SymmetricAlgorithm aes = Rijndael.Create();
            aes.Key = Encoding.UTF8.GetBytes(IDKey);
            aes.IV = _key1;
            byte[] decryptBytes = new byte[cipherText.Length];
            using (MemoryStream ms = new MemoryStream(cipherText))
            {
                using (CryptoStream cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    cs.Read(decryptBytes, 0, decryptBytes.Length);
                    cs.Close();
                    ms.Close();
                }
            }
            return Encoding.UTF8.GetString(decryptBytes).Replace("\0", "");   ///將字符串後尾的‘\0‘去掉
        }

        public static string AESDecryptName(string showText)
        {
            byte[] cipherText = Convert.FromBase64String(showText);

            SymmetricAlgorithm aes = Rijndael.Create();
            aes.Key = Encoding.UTF8.GetBytes(nameKey);
            aes.IV = _key1;
            byte[] decryptBytes = new byte[cipherText.Length];
            using (MemoryStream ms = new MemoryStream(cipherText))
            {
                using (CryptoStream cs = new CryptoStream(ms, aes.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    cs.Read(decryptBytes, 0, decryptBytes.Length);
                    cs.Close();
                    ms.Close();
                }
            }
            return Encoding.UTF8.GetString(decryptBytes).Replace("\0", "");   ///將字符串後尾的‘\0‘去掉
        }

        public static void genKey()
        {

            var generator = new RijndaelManaged();
            var key = Convert.ToBase64String(generator.Key);
            byte[] iv = generator.IV;

            Console.WriteLine(key);
            Console.WriteLine(generator.IV);
        }
    }

Key:為32位的字符

　byte:0-255之間的16進制數字

AES加解密