> Deleting data securely involves overwriting all the previously allocated filesystem blocks with random data. No one should be able to discern that now-empty s

> Deleting data securely involves overwriting all the previously allocated filesystem blocks with random data. No one should be able to discern that now-empty space had data in it as of some specific recent datetime. If it was like a HDD maybe that could work, but most modern solid state storage doesn't work like that any more. You can't reliably overwrite any data, because the default is to write any new data in an empty sector (sort of, it has to do with how flash storage works, because of "wear leveling"), which is managed at the hardware level of the storage itself, so you also can't really tell the OS to do something else.