> If the crypto is strong, and the key never exfiltrated, then this may be even better than an explicit overwrite, which on some media (like magnetic drives) may still leave trace hints of the old data that advanced techniques could recover.
The idea that magnetic drives left readable traces behind after an overwrite is a myth (especially of modern drives; if I recall the article I'm thinking of correctly the myth may have had a _slim_ chance of being true with old drives [like 100MB days]).
The idea was that, since the drive head doesn’t pass over precisely the same area on the track every time it writes to the disk, the track has to be wide enough to account for this lack of precision. Thus, a single overwrite pass could leave a portion of the track’s edge unchanged and readable with an electron microscope or something.
I always figured that a write wouldn't change the magnetic field 100%. Say it's 90% effective at changing the magnetic field. There's now four options:
The idea that magnetic drives left readable traces behind after an overwrite is a myth (especially of modern drives; if I recall the article I'm thinking of correctly the myth may have had a _slim_ chance of being true with old drives [like 100MB days]).