>> Hint: If it were economically feasible to recover overwritten data, >> the large data-recovery companies would offer that service.
And perhaps they do, but don't advertise it because only governments and very large companies (and other organizations with similarly deep pockets) can afford it. How often do you think there is data worth spending that much to recover? Most organizations with data worth that much don't let the drives out in any form there's any chance of recovering the data from. (I'm not talking slegehammer destruction; I'm talking thermite.) The only real market I can see is to recover accidentally overwritten data, and that requires that somehow a drive had the only copy (unlikely) _and_ got so carelessly treated as to get overwritten (also unlikely). How long does it take to extract gigabytes of data by using an atomic force microscope to image each bit's recording area? I don't know how fast they are, but whatever fraction of a second it takes to extract a byte, reading a gigabyte of disk will take an equal fraction of a gigasecond, which I shall let you work out for yourselves. It'd have to be a comparatively small amount of data and you'd have to know at least approximately where on the disk to look for it, for recovery to be economic.... /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTML [email protected] / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B _______________________________________________ Fun and Misc security discussion for OT posts. https://linuxbox.org/cgi-bin/mailman/listinfo/funsec Note: funsec is a public and open mailing list.
