uses XceedEncryptionLib_TLB 

var
  xEnc : TXceedEncryption; 
  xRijndael : DXceedRijndaelEncryptionMethod; 
  vaSource : OleVariant; 
begin
  xEnc := TXceedEncryption.Create( self ); 
  xEnc.License( 'your license key' );

  xRijndael := CoXceedRijndaelEncryptionMethod.Create(); 

  try 
    xRijndael.SetSecretKeyFromPassPhrase( 'This is a weak pass phrase!', 128 ); 
    xEnc. EncryptionMethod := xRijndael; 

    vaSource := 'This is the data to encrypt'; 

    xEnc.WriteFile( vaSource, efpEncrypt, true, 'c:\temp\encrypted.aes', false ); 

    ShowMessage( 'Encryption successful!' ); 

  except 
    on xErr : Exception do 
      ShowMessage( xErr.Message ); 
  end; 

  xEnc.Free; 
end;