System.Security.Cryptography.CryptographicException：要解密的数据长度无效吗？

Question

我希望将数字字符串加密，然后解密并以ASCII格式返回。 但是在下面的静态方法中，在解密块中它给出了一个错误，因为长度无效。我的字符串应该像这样以xx-xx-xx的代码生成，每2位数字后会插入一个hypen，但是无法解密，请问要解密的数据长度是否无效？

如何解决错误，请帮忙！

以下是我的代码：-   encryptionText = 9007315596089，key ='This Is MySecure'，iv ='Encrption'到以下方法

private static string Decrypt(string encryptedText, string key, string iv)
{
    //encryptedText = encryptedText.Insert(2, "-");
    int length = encryptedText.Length;
    byte[] keyBytes = getKeyBytes(key);
    byte[] ivBytes = getIVBytes(iv);
    string encrytedTextNew = "";

    //for (int i = 2; i < encrytedTextNew.Length - 1; i += 3)
    //{
    //    if (encrytedTextNew.Count(c => c == '-') >= 3) i++;
    //    encrytedTextNew = encrytedTextNew.Insert(i, "-");
    //}

    char[] encrytArray = encryptedText.ToCharArray(0, encryptedText.Length);
    for (int i = 0; i < encryptedText.Length; i++)
    {
        if (i != 0)
        {
            int j = i + 1;
            //if (j == 14)
            //{
            //    encrytedTextNew = encrytedTextNew +"-";
            //    break;
            //}
            if (j % 2 == 0)
            {
                encrytedTextNew = encrytedTextNew + encrytArray[i] + "-";
            }
            else
            {
                encrytedTextNew = encrytedTextNew + encrytArray[i];
            }
        }
        else if (i == 0)
        {
            encrytedTextNew = encrytedTextNew + encrytArray[i];
        }
    }

    encrytedTextNew = encrytedTextNew.Remove(encrytedTextNew.Length-1);
    //encrytedTextNew = encrytedTextNew + "7";
    RijndaelManaged aes = new RijndaelManaged();
    aes.Mode = CipherMode.CBC;
    aes.Key = keyBytes;
    aes.IV = ivBytes;
    ICryptoTransform encrypto = aes.CreateDecryptor();

    byte[] plainTextByte = Array.ConvertAll<string, byte>(encrytedTextNew.Split('-'), s => Convert.ToByte(s, 16));
    int len = plainTextByte.Length;
    **byte[] CipherText = encrypto.TransformFinalBlock(plainTextByte,0, plainTextByte.Length - 1);**
    return ASCIIEncoding.UTF8.GetString(CipherText);
}