How to do secure encryption and decryption using DOTNET code

How to do secure encryption and decryption using DOTNET code   Following code will give you the way to do key based encryption and decryption, this code using Dotnet Cryptography class and vb.net. I have tested following code with Dotnet framwork 2.0 and window XP.   Namespace   Imports System.Security.Cryptography   Global Variable   'Blow will be the Key to do Encryption and Decryption Private Shared TheKey() As Byte = {&H12, &H34, &H56, &H78, &H9A, &HBC, &HDE, &HFF} Private Shared Vector() As Byte = {&H11, &H22, &H33, &H44, &H55, &H66, &H77, &H88}   Encryption   Public Shared Function GetEncryptedData(ByVal message As String) As String   Dim desServiceProvider As New DESCryptoServiceProvider Dim memoryStream As New MemoryStream Dim in_buf(), out_buf() As Byte   'Check for empty string If message = String.Empty Then     Return String.Empty End If   ' put the cleartext into the input buffer in_buf = Encoding.ASCII.GetBytes(message)   Try 'create an DES Encryptor output stream Dim crStream As New CryptoStream(memoryStream, desServiceProvider.CreateEncryptor(TheKey, Vector), CryptoStreamMode.Write) crStream.Write(in_buf, 0, in_buf.Length) crStream.FlushFinalBlock()    ' read the ciphertext into the output array  out_buf = memoryStream.ToArray    memoryStream.Close()  crStream.Close()  Catch ex As System.Security.Cryptography.CryptographicException      ' if encryption fails,return an empty string      Return String.Empty End Try        Return Convert.ToBase64String(out_buf)   End Function   Decryption   Public Shared Function GetDecryptedData(ByVal message As String) As String   Dim desServiceProvider As New DESCryptoServiceProvider Dim memoryStream As New MemoryStream Dim in_buf(), out_buf() As Byte   'Check for empty string If message = String.Empty Then Return String.Empty End If   ' put the ciphertext into the input buffer Try    in_buf = Convert.FromBase64String(message)    Catch ex As System.FormatException    ' if the string isn't in the correct format,  then return empty string Return Return String.Empty End Try   Try   ' Create an DES Decryptor stream Dim crStream As New CryptoStream(memoryStream, desServiceProvider.CreateDecryptor(TheKey, Vector), CryptoStreamMode.Write) crStream.Write(in_buf, 0, in_buf.Length) crStream.FlushFinalBlock()   ' read the cleartext into the output array out_buf = MemoryStream.ToArray   MemoryStream.Close() crStream.Close() Catch ex As System.Security.Cryptography.CryptographicException   ' if decryption fails, just silently return an empty string   Return String.Empty  End Try      Return Encoding.ASCII.GetString(out_buf)   End Function   Note:   If your project requirement is to do simple encryption decryptions then see below link http://riteshk.blogspot.com/2004/07/how-to-do-encryption-and-decryption.html   If you are using Microsoft enterprise library and your project requirement is very specific to use any standard framework to do encryption and decryption then see following link http://msdn.microsoft.com/en-us/library/cc309163.aspx   If you want to encrypt your app.config file the see following link http://riteshk.blogspot.com/2008/05/programatically-configuration-files.html