Permanent Eraser :: Frequently Asked Questions

• How is Permanent Eraser used?
  • Erase the Trash: Double-click on the Permanent Eraser icon, and it will erase the contents of your Trash.
  • Erase selected files: Select the files to delete in the Finder, and drag them onto the Permanent Eraser icon. Permanent Eraser will then only erase those specific files.
  • Erase optical discs: Select a rewritable optical disc (CD-RW or DVD-RW) and drag it onto the Permanent Eraser icon to completely write over the disc's data.

• What are the advantages of using Permanent Eraser over Mac OS X's Secure Empty Trash feature?
  • Security - The Secure Empty Trash feature uses the US DoD method of overwriting files 7 times, whereas Permanent Eraser uses the Gutmann Method which uses a special pattern to overwrite files 35 times.
  • Tracking - Permanent Eraser shows the real-time progress of the files while they are being erased, but the Mac Finder's progress bar updates only after an entire file has been deleted.
  • Flexibility - Mac OS X only securely erases files that are in the Trash, but Permanent Eraser can erase individual files and rewritable discs as well as the files in the Trash.
  • Legacy Support - Secure Empty Trash and Erase Free Space were removed in OS X El Capitan, but Permanent Eraser continues to provide these capabilities for computers which still use mechanical hard drives.

• Will Permanent Eraser run on Intel-based Macs?

  Yes. Version 2.2 and later of Permanent Eraser runs natively on Intel-based Macs. Permanent Eraser 2.8.1 was the last version to run on PowerPC-based Macs.

• Will Permanent Eraser run on Apple Silicon-based Macs?

  Yes. Permanent Eraser 2.9 can run on Apple Silicon-based Macs up to macOS 27 Golden Gate (with Rosetta 2 installed). Permanent Eraser will not run on versions of macOS past version 27.

• Can Permanent Eraser erase CD-RW and DVD-RW discs?

  Yes. This was a new feature introduced with Permanent Eraser 2.3.

• Are resource forks erased?

  Yes, resource forks are erased.

• Can aliases be erased?

  Yes, aliases can be erased if they are in the Trash.

• Are file names mangled?

  Yes, before the file is unlinked, the original file name is renamed with a random set of characters to make it even more difficult to discover the former name of the file.

• Is there a way to hide the warning after Permanent Eraser starts?

  Permanent Eraser 2.2.3 introduced a feature where a dialog box would appear once the application had launched. This warning gives the user the option to either quit or continue with the program. To prevent this warning from appearing, hold down the Option key when launching Permanent Eraser.
  
  To make this setting permanent, open up the General Preferences and uncheck the Warn before erasing option.
  
  Permanent Eraser 2.4 (and later) offers a feature in the warning dialog to suppress this warning. Click the "Do not show this message again" checkbox and the warning will be disabled.

• Can the sound effects be disabled?

  Yes. Go to the General Preferences and uncheck the Play sounds option.

• Does Permanent Eraser shred free space?

  Free space can be erased by using the Erase Free Space Automator action.

• Does Permanent Eraser run on Mac OS 9 or earlier?

  No. Permanent Eraser has been developed to run on Mac OS X only. If you need a utility to erase files on Mac OS 9 (or earlier), try Burn (Download).

• Can Permanent Eraser erase data from a flash-based drive (SSD, thumb drive, etc.)?

  Due to the differences in how flash-based drives read and write data (versus traditional magnetic media hard drives), it is not recommended to use Permanent Eraser or any other traditional hard drive wiping method on flash-based drives. At this time, there does not seem to be a reliable method via software to erase data from flash-based drives. The best advice is to encrypt your drive, which can help provide some measure of protection for your data.

  However, if Permanent Eraser that a file is located on a SSD, the file will only be erased once to prevent unnecessary overwriting.

• Permanent Eraser 2.5.3 in the Mac App Store version doesn't work with macOS Sierra and later.

  This is a known issue with Permanent Eraser 2.5.3 which can be resolved by upgrading to the latest version of Permanent Eraser. Permanent Eraser has been updated for the Mac App Store which resolves the problem encountered with macOS Sierra.
  
  Technical details: This issue was caused by Apple removing the srm utility from macOS Sierra, which is a necessary component for Permanent Eraser to run. Later versions of Permanent Eraser included a custom version of srm, so the application is not dependent upon the operating system to provide this utility.

• What are the known issues?
  • An alias can only be deleted if it is in the Trash. Otherwise, trying to delete an alias will delete the original file, but not the alias.
  • Some files not owned by the current user may not be able to be immediately deleted. You will be prompted to enter in administrator credentials to authorize Permanent Eraser to erase this file. Files on a read-only disk, such as a CD-ROM, cannot be erased. This feature is not available in the Mac App Store version of this app.
  • The contextual plug-in doesn't appear in macOS Mojave: Refer to the document Enabling the Erase Service for Permanent Eraser in macOS Mojave to resolve this issue.
  • Permanent Eraser is having problems erasing files in the Trash: Refer to the document Enabling Full Disk Access for Permanent Eraser in macOS Catalina to resolve this issue.

Resources

• Gutmann Method
• Secure Deletion of Data from Magnetic and Solid-State Memory
• How to REALLY erase a hard drive
• Disk Drive Secure Erase
• Apple's srm source code
• Sourceforge's srm project
• Reliably Erasing Data from Flash-Based Solid State Drives
• SAFE: Fast, Verifiable Sanitization for SSDs