If you want to add a keyboard shortcut for Secure Empty Trash, you can do so with the following steps:
- Launch System Preferences by clicking its icon in the Dock.
- Select the Keyboard & Mouse preference panel.
- Select the Keyboard Shortcuts tab.
- Beneath the list of keyboard shortcuts in the middle of the window, you’ll see plus (+) and minus (–) sign buttons. Click the plus button to add an item to the list.
- In the sheet that slides out of the window’s titlebar, select Finder from the Application pop-up menu.
- In the Menu Title field, type in “Secure Empty Trash” (without the quotes). This tells the Finder to look for this menu item.
- Tab down to the Keyboard Shortcut field, and create a keyboard shortcut that works for you. For example, you could set the keyboard shortcut for Secure Empty Trash to Control-Shift-Command-D.
- Quit System Preferences (Command-Q).
- Because you’ve made changes to the Finder, you’ll need to restart it. To do this, go to Apple menu > Force Quit (Option-Command-Esc) to open the Force Quit window.
- Select the Finder and then click the Relaunch button. After clicking the Relaunch button, you’ll be prompted with an alert dialog box, asking if you really want to relaunch the Finder. Since this is what you want to do, click on the Relaunch button in the sheet.
- After a brief pause, your Dock quits and restarts.
- Close the Force Quit window by clicking on the red close window icon in the window’s titlebar.
Now if you go to the Finder’s application menu, you’ll see that the keyboard shortcut you’ve added for Secure Empty Trash shows up in the menu. Before using this shortcut, just make sure that the files in your Trash are files that you’ll never ever need again.