If you have a hard copy of a document or form that you never want anyone to see, you can shred it, burn the bits, and scatter them to the four corners of the Earth in hopes that the CSI team never finds them. It’s effective enough for physical documents but when it comes to files on your computer, deleting a file from your hard disk and your trash sounds as if it should be enough to get rid of them. However, these files can still be recovered either by using file recovery apps, or employing people from CSI. We’ve covered a tip on permanently erasing files from OS X using the Terminal, and where it is sufficient if you seldom need to securely delete files, the method isn’t all that convenient for frequent use or if a lot of files are involved. Incinerator is a free app available in the Mac App Store that provides a more effective way to delete your files. It’s a file shredder that gives you free rein to choose how many times a file is shredded. You can choose to keep a dummy copy of the shredded file, or have the app delete it automatically once it’s been shredded.
To shred a file with Incinerator, drag & drop it on to the app’s Dock icon or open it from the app’s menu. You can only shred one file at a time, and there is no support for shredding entire folders at once. It also can’t shred applications yet, but support for both is in the pipeline.
When a file is added to Incinerator, a window opens asking you how many times you would like to incinerate i.e. shred, the file. If the ‘Erase File After Incineration’ option is unchecked, the file will be shredded but not removed from your system. It will continue to appear at its original location, but will obviously not open since it has been shredded. If you check the ‘Use Non-Blocking Random Functions’ option, the file will be shredded faster, but the shredding will not be as thorough.
The time it takes to shred a file depends on its size. To some extent, it depends on how good the app itself is, but the number of times you choose to shred a file as well as the size of the file are the factors that have the largest impact on the time it takes to shred it.
Incinerator integrates with Mountain Lion’s Notification Center and will inform you when it has finished shredding a file. This is useful when you’re shredding large files that are taking up considerable time. Incinerator also reports how long it took to shred a file. We tested it with a 1.5MB PNG file, setting Incinerator to shred it 10 times, and the process completed in approximately 5 seconds.