Secure delete has become quite difficult to achieve, if it is on a SSD then you may only be safe with an ATA command, but not all drives will even do that right[1]. It is even hard to be sure that you have over-written every block anyway, due to over-provisioning.<p>Filesystems can also make this quite difficult (and that is without considering snaphots), most journalling and log-structured filesystems break the old shred [2] program for instance.<p>[1] <a href="https:&#x2F;&#x2F;www.usenix.org&#x2F;legacy&#x2F;event&#x2F;fast11&#x2F;tech&#x2F;full_papers&#x2F;Wei.pdf" rel="nofollow">https:&#x2F;&#x2F;www.usenix.org&#x2F;legacy&#x2F;event&#x2F;fast11&#x2F;tech&#x2F;full_papers&#x2F;...</a>
[2] man shred