DES加密/解密

/// <summary>
        /// DES加密(数据加密标准，速度较快，适用于加密大量数据的场合)
        /// </summary>
        /// <param name="EncryptString">待加密的密文</param>
        /// <param name="EncryptKey">加密的密钥</param>
        /// <returns>returns</returns>
        public static string DESEncrypt(string EncryptString, string EncryptKey)
        {
            if (string.IsNullOrEmpty(EncryptString))
            {
                EncryptString = ConfigurationHelper.GetArasDatabaseName();
            }

            if (string.IsNullOrEmpty(EncryptKey) || EncryptKey.Length != 8)
            {
                EncryptKey = "ArasInnovator";
            }
            byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
            string m_strEncrypt = "";
            DESCryptoServiceProvider m_DESProvider = new DESCryptoServiceProvider();

            try
            {
                byte[] m_btEncryptString = Encoding.Default.GetBytes(EncryptString);
                MemoryStream m_stream = new MemoryStream();
                CryptoStream m_cstream = new CryptoStream(m_stream, m_DESProvider.CreateEncryptor(Encoding.Default.GetBytes(EncryptKey), m_btIV), CryptoStreamMode.Write);
                m_cstream.Write(m_btEncryptString, 0, m_btEncryptString.Length);
                m_cstream.FlushFinalBlock();
                m_strEncrypt = Convert.ToBase64String(m_stream.ToArray());
                m_stream.Close(); m_stream.Dispose();
                m_cstream.Close(); m_cstream.Dispose();
            }
            catch (IOException ex) { throw ex; }
            catch (CryptographicException ex) { throw ex; }
            catch (ArgumentException ex) { throw ex; }
            catch (Exception ex) { throw ex; }
            finally { m_DESProvider.Clear(); }

            return m_strEncrypt;
        }

/// <summary>
        /// DES 解密(数据加密标准，速度较快，适用于加密大量数据的场合)
        /// </summary>
        /// <param name="DecryptString">待解密的密文</param>
        /// <param name="DecryptKey">解密的密钥</param>
        /// <returns>returns</returns>
        public static string DESDecrypt(string DecryptString, string DecryptKey)
        {
            if (string.IsNullOrEmpty(DecryptString))
            {
                DecryptString = ConfigurationHelper.GetArasDatabaseName();
            }

            if (string.IsNullOrEmpty(DecryptKey) || DecryptKey.Length != 8)
            {
                DecryptKey = "ArasInnovator";
            }

            byte[] m_btIV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
            string m_strDecrypt = "";
            DESCryptoServiceProvider m_DESProvider = new DESCryptoServiceProvider();

            try
            {
                byte[] m_btDecryptString = Convert.FromBase64String(DecryptString);
                MemoryStream m_stream = new MemoryStream();
                CryptoStream m_cstream = new CryptoStream(m_stream, m_DESProvider.CreateDecryptor(Encoding.Default.GetBytes(DecryptKey), m_btIV), CryptoStreamMode.Write);
                m_cstream.Write(m_btDecryptString, 0, m_btDecryptString.Length);
                m_cstream.FlushFinalBlock();
                m_strDecrypt = Encoding.Default.GetString(m_stream.ToArray());
                m_stream.Close(); m_stream.Dispose();
                m_cstream.Close(); m_cstream.Dispose();
            }

            catch (IOException ex) { }
            catch (CryptographicException ex) {  }
            catch (ArgumentException ex) {  }
            catch (Exception ex) {  }
            finally { m_DESProvider.Clear(); }

            return m_strDecrypt;
        }

【原文出处】http://www.51aras.com/?id=8