Private Shared Sub EncryptData(inName As String, outName As String, _
   tdesKey() As Byte, tdesIV() As Byte)

    'Create the file streams to handle the input and output files.
    Dim fin As New FileStream(inName, FileMode.Open, FileAccess.Read)
    Dim fout As New FileStream(outName, FileMode.OpenOrCreate, _
       FileAccess.Write)
    fout.SetLength(0)

    'Create variables to help with read and write.
    Dim bin(100) As Byte 'This is intermediate storage for the encryption.
    Dim rdlen As Long = 0 'This is the total number of bytes written.
    Dim totlen As Long = fin.Length 'This is the total length of the input file.
    Dim len As Integer 'This is the number of bytes to be written at a time.
    Dim tdes As New TripleDESCryptoServiceProvider()
    Dim encStream As New CryptoStream(fout, _
       tdes.CreateEncryptor(tdesKey, tdesIV), CryptoStreamMode.Write)

    Console.WriteLine("Encrypting...")

    'Read from the input file, then encrypt and write to the output file.
    While rdlen < totlen
        len = fin.Read(bin, 0, 100)
        encStream.Write(bin, 0, len)
        rdlen = rdlen + len
        Console.WriteLine("{0} bytes processed", rdlen)
    End While

    encStream.Close()
End Sub

private static void EncryptData(String inName, String outName, byte[] tdesKey, byte[] tdesIV)
{    
    //Create the file streams to handle the input and output files.
    FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
    FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
    fout.SetLength(0);

    //Create variables to help with read and write.
    byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
    long rdlen = 0;              //This is the total number of bytes written.
    long totlen = fin.Length;    //This is the total length of the input file.
    int len;                     //This is the number of bytes to be written at a time.

    TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();          
    CryptoStream encStream = new CryptoStream(fout, tdes.CreateEncryptor(tdesKey, tdesIV), CryptoStreamMode.Write);

    Console.WriteLine("Encrypting...");

    //Read from the input file, then encrypt and write to the output file.
    while(rdlen < totlen)
    {
        len = fin.Read(bin, 0, 100);
        encStream.Write(bin, 0, len);
        rdlen = rdlen + len;
        Console.WriteLine("{0} bytes processed", rdlen);
    }

    encStream.Close();                     
}

void EncryptData( String^ inName, String^ outName, array<Byte>^tdesKey, array<Byte>^tdesIV )
{

   //Create the file streams to handle the input and output files.
   FileStream^ fin = gcnew FileStream( inName,FileMode::Open,FileAccess::Read );
   FileStream^ fout = gcnew FileStream( outName,FileMode::OpenOrCreate,FileAccess::Write );
   fout->SetLength( 0 );

   //Create variables to help with read and write.
   array<Byte>^bin = gcnew array<Byte>(100);
   long rdlen = 0; //This is the total number of bytes written.

   long totlen = (long)fin->Length; //This is the total length of the input file.

   int len; //This is the number of bytes to be written at a time.

   TripleDESCryptoServiceProvider^ tdes = gcnew TripleDESCryptoServiceProvider;
   CryptoStream^ encStream = gcnew CryptoStream( fout,tdes->CreateEncryptor( tdesKey, tdesIV ),CryptoStreamMode::Write );
   Console::WriteLine( "Encrypting..." );

   //Read from the input file, then encrypt and write to the output file.
   while ( rdlen < totlen )
   {
      len = fin->Read( bin, 0, 100 );
      encStream->Write( bin, 0, len );
      rdlen = rdlen + len;
      Console::WriteLine( "{0} bytes processed", rdlen );
   }

   encStream->Close();
}