Hi Gary,
I am using Sierra (10.12.4) on a MacBook Pro (mid 2014). I have enabled File Vault.
I have some small yet sensitive spreadsheets(<100k) that I have encrypted using the resident Disc Utility App. After creating an encrypted "Blank Image," I "move" the files into the mounted folder and then close the .dmg file. Is this a robust security measure? Does the unencrypted plain text still reside on the SSD? Could a recovery program access them? Is this a valid method of secure deleting files I no longer need? Thanks in advance for your help. PS - I have enjoyed the recent scripting episodes in your weekly newsletter. I'd like to see more. ----- David Russell
The old method of securely deleting files was for hard drives -- spinning disks. That method is not used on solid-state drives as it isn't necessary since files, more or less, don't leave behind traces of bits after being deleted. Even if they did, it would require someone to steal your computer, get the hard drive out, and run some pretty sophisticated things to extract the data. Spy stuff. Not something typical users really need to worry about.
If you are concerned about security today, you should just turn on File Vault in System Preferences. That encrypts all of your data so it is safe while you are using it, not just after it is deleted.
Your method of securing the file now is fine. The file you deleted when you "moved" it to the disk image is gone.
Hi Gary,
If you enabled File Vault, anything left behind after deletion is still encrypted. So if anyone did manage to recover the data, they would not be able to read.
Aeckert: Exactly.