C#DESC解密有关问题

C#DESC解密问题
我在网上找了个实例，实际运行测试了下，可运行到byte[] result = desencrypt.TransformFinalBlock(data, 0, data.Length);时老是报CryptographicException异常，请哪位高手指点下哪里有错，还是参数错误。
 public string DecryptString(string inputInfo, string sKey)
        {
            string[] sInput = inputInfo.Split("-".ToCharArray());
            byte[] data = new byte[sInput.Length];
            for (int i = 0; i < sInput.Length; i++)
            {
                data[i] = byte.Parse(sInput[i], NumberStyles.HexNumber);
            }
            DESCryptoServiceProvider DES = new DESCryptoServiceProvider();
            DES.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
            DES.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
            ICryptoTransform desencrypt = DES.CreateDecryptor();
            byte[] result = desencrypt.TransformFinalBlock(data, 0, data.Length);
            return Encoding.UTF8.GetString(result);
        }
[解决办法]

       /// <summary>
        /// DES对称加密方法
        /// </summary>
        /// <param name="InitData">原始待加密数据</param>
        /// <param name="SecretKey">加密密钥,密钥长度必须为八位有效英文字符</param>
        public static string EncryptData(object InitData, string SecretKey) 
 
        {
            try
            {
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                //把字符串放到byte数组中    
                Byte[] inputByteArray = Encoding.Default.GetBytes(InitData.ToString());
                //建立加密对象的密钥和偏移量
                des.Key = ASCIIEncoding.ASCII.GetBytes(SecretKey);
                //原文使用ASCIIEncoding.ASCII方法的GetBytes方法 
                des.IV = ASCIIEncoding.ASCII.GetBytes(SecretKey);
                //使得输入密码必须输入英文文本
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                StringBuilder ret = new StringBuilder();
                foreach (Byte b in ms.ToArray())
                {
                    ret.AppendFormat("{0:X2}", b);
                }
                ret.ToString();
                return ret.ToString();
            } 
 
            catch
            {
                return "";
            }
        }

        /// <summary>
        /// DES对称解密方法
        /// </summary>
        /// <param name="EncryptedData">待解密数据</param>
        /// <param name="SecretKey">解密密钥,必须是加密时的密钥,密钥长度必须为八位有效英文字符,例如"12secret"</param>
        public static string DecryptData(object EncryptedData, string SecretKey)
        {
            try
            {
                string pToDecrypt = EncryptedData.ToString();
                DESCryptoServiceProvider des = new DESCryptoServiceProvider();
                Byte[] inputByteArray = new byte[pToDecrypt.Length / 2];
                for (int x = 0; x < pToDecrypt.Length / 2; x++)
                {
                    int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
                    inputByteArray[x] = (byte)i;
                }
                //建立加密对象的密钥和偏移量，此值重要，不能修改 
                des.Key = ASCIIEncoding.ASCII.GetBytes(SecretKey);
                des.IV = ASCIIEncoding.ASCII.GetBytes(SecretKey); 
 
                MemoryStream ms = new MemoryStream();
                CryptoStream cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
                cs.Write(inputByteArray, 0, inputByteArray.Length);
                cs.FlushFinalBlock();
                return System.Text.Encoding.Default.GetString(ms.ToArray());
            }
            catch
            {
                return "";
            }
        }