How to permanently secure erase/wipe a MacOS SSD Drive

[chrfr]

Thanks for the responses. I think in terms of encrypting/secureErasing I have done everything that can be done.

So really in situations like this there is only one remaining thing left that people can do if in this situation one wants certainty. And that is to install a highly effective file recovery tool to undelete files once thought erased. I knew a number of these tools on Windows, but don't really know any on Mac.

If after running these tools, NO file that was once deleted can be found, then indeed we know it is gone forever. Any ideas what I can install?

No, the only way to be 100% certain no files can be recovered is to physically destroy the storage.

 

[MikeGreo]

No, the only way to be 100% certain no files can be recovered is to physically destroy the storage.

Thanks for the reply, however I am intent on installing an effective recovery software tool and see what can be found. What software can I install on a MacOS to do this?

 

[KALLT]

There are indications that macOS uses some form of hardware-based data destruction on Apple-branded SSDs when doing a disk reformat, through trim, ATA secure erase or otherwise. In such cases, a software-based erase is already superfluous. Apple-branded SSDs also use trim frequently when deleting data, so the chance of deleted data remaining there is, compared to HDDs, small. Aftermarket SSDs must instead rely on vendor software to erase data, such as Samsung Magician. Of course, for the end user this data destruction is not verifiable without analytical tools, experience and a lot of time.

Data recovery tools can only restore data on a best-effort basis and cannot give the assurance that there is no recoverable data left. Such recovery is incredibly difficult on fragmented data and impossible on overwritten or trimmed data blocks. Just because recovery software could not piece data back together into a usable file is no evidence that there is no partial data left.

If you are serious about data protection, you will use FileVault or like from the start and stick with it. Enabling FileVault shortly before formating the disk is not 100% reliable either, as some SSDs may use over-provisioning and keep unencrypted data on those blocks.