Defining Custom Wipe Methods

XL Delete 1.1 introduced the new wipe engine "Engine2" which allows users to create their own complex wipe methods. Users can create an unlimited amount of customized methods which can range in complexity from the simple random wipe to the very complex and secure Gutmann wipe.

This dialog will show all the existing custom wipe methods, allow you to delete or edit existing custom wipe methods, or create a new wipe method. The example screenshot shows an existing custom wipe method named Random 7 which is just a 7-pass wipe with pure random data. If we wanted to delete Random 7, we would just select it and choose "Remove Selected Wipe Type". If we wanted to edit it, we would choose "Edit Selected Wipe Type" which would bring up the Custom Wipe Editor:

We can edit all parts of the Random 7 method with this editor. The left hand side is the wipe definition view and the right hand side is the editor. You can remove any pass, and add new ones. See below for information on using the editor.

The first thing to do is to plan out your new custom wipe method. Determine what you want your wipe method to do and how many passes to use. Once you have planned out your new wipe method, choose "Add/Edit" to bring up a blank Editor window:

The first thing to do is to give the wipe method a name. Enter "My First Custom Wipe" in the wipe name text box. Now you will want to start building the wipe method one pass at a time.

The first pass will be a random pass. Make sure that the Wipe with random data option is selected and press "Add Pass".

We will add the second pass in Text Mode. Select the Text Mode option. You will notice that the text box becomes enabled. Enter "Secret Stuff - Keep Out" in the text box and press "Add Pass". Now you will see two Pass items in the wipe definition view.

We will add the final pass in Hex Mode. Hex mode allows you to create advanced passes by specifying bytes to use for the wipe pass. We can specify single bytes or a sequence of bytes. Bytes must be specified in hex ie: 0x00. Byte sequences must be separated by commas ie: 0x00,0x01,0x02. We will use a sequence from the Gutmann method (0x92, 0x49, 0x24) for this example.

Your first custom wipe method is now complete. It will wipe a file first with random data, then with the text "Secret Stuff - Keep Out", then again with random data, and finally with on the the passes from the Gutmann method.

Each pass will specify if it is a random pass and the data that it will use to wipe in both text and hex.

Once you have reviewed your wipe, choose Add Wipe Type to save your first custom wipe. It will now show up in the Custom Wipe Manager and will now be selectable as a wipe type in the Settings dialog by choosing the custom option and choosing "My First Custom Wipe" from the drop down menu.

No. The security remains the same. The wipes work on bytes and the editor will convert any data entered in Text Mode or Hex Mode to the equivalent bytes. You can in fact define the same pass with both options. For example: Entering "1234" in Text Mode is the same as entering "0x31,0x32,0x33,0x34" in Hex Mode.

Hex Mode allows you to define passes that use data that cant be easily inputted by pressing one of the keys available on the keyboard. This gives you complete control to use any kind of byte for the wipe. Hex Mode will allow you to easily create wipe methods that are as complex as the ones built into XL Delete.

Yes you can. The built in methods are just custom methods that are defined within the program code.

Is there a performance difference in using a custom method rather than one of the built in methods?

That depends on the number of passes that your custom wipe method has. If we were to compare a built in method to it's equivalent custom method then the only performance difference would be at the beginning of a wipe because the engine would have to read the custom wipe definition from a file, which would only be a couple of milliseconds of difference.