Letter Re: Taking Out the Trash: Secure Deletion
HJL, Technically, short of physically destroying flash media, there is no way to insure that something is securely erased. This applies to USB drives, SD cards of all sizes, and even SSD disk drives. It applies less so to magnetic hard drives. Hard drives can drift so there can be a thin shadow of old data, but that is something only someone with very deep pockets can recover, and it would be hit and miss. With flash drives, data is eventually erased, but what normally happens is the prior place the data was stored is mapped as “obsolete, erase when …