Overview
Files may be securely deleted using File Shredder. File Shredder is a free desktop application available on Windows for shredding (destroying) unwanted files beyond recovery. On Mac computers, files may be securely deleted using a feature built into the operating system.
Why should you securely delete/shred information?
When files are deleted using the common "delete" operation, information is only removed from files so they can't be found by the operating system. File recovery software can be used to recover this information by taking advantage of shortcomings in the standard delete operation. A program capable of overwriting the file data with random binary must be used in order to remove files permanently from your system. This process is often called shredding.
What should be shredded?
Files that need to be completely deleted beyond recovery should be shredded. Before shredding a file, ensure that you are not violating any State Records Laws or Sunshine Laws. Any information that needs to be maintained for Public Record should NOT be shredded (e.g., a student's proof of residency, student records, payment receipts, etc.). However, any files that may contain confidential information that are not public record should be shredded if they are no longer needed (e.g., an Excel Document used to move Social Security Numbers from one location to another that will not be used again).
For more information, please see University Policy FIN 3.02-2.14 and the Records Management Overview.
How to shred files
File Shredder is a reliable tool that can be used to shred files. It is available free under GNU licence. You may download File Shredder and use it without any restrictions. File Shredder is a powerful program that shreds files with the option of 5 different shredding algorithms, each slightly stronger than the previous. Additionally, File Shredder has an integrated Disk Wiper, which uses a shredding algorithm to wipe unused disk space. More information may be found at the File Shredder Website.
Shredding Files using File Shredder
- Install File Shredder from the link above.
- Open File Shredder.
3. Select the files you wish to shred by clicking "Add File(s)" or "Add Folder."
4. Once the files have been added, click "Shred Files Now.."
For additional assistance using File Shredder, please check their Online Help page.
The ability to securely delete files is built into the OS on Macs.
To securely delete a file:
- Add the file to the Trash Bin.
- Choose Finder from the menu bar.
- Click "Secure Empty Trash..." When you do this, not only is the file removed from the Mac’s directory, but the hard drive space it occupied is overwritten with random binary digits.
You may also adjust your settings so that files are removed securely each time you empty the trash. To adjust this setting:
- Click Finder from the Menu Bar.
- Select Preferences.
- Click Advanced.
- Check the box to "Empty Trash securely."
