FWIW the theory I read was they shift the read head just slightly to one side or the other and as some shake is always present the sides can be read and distinguished from the new data.jafadmin wrote:I have an associate that is a DOJ certified Forensic IT Specialist. These guys have really expensive hardware and software designed to do just exactly what you said.Burn_IT wrote: Even with data overwrite on magnetic disks it is possible (though expensive) to retrieve prior data after a few passes. That is why DOD standards say seven overwrites with different random data each time.
It is also very difficult to "clean" SSD type storage media because of the randomising. The only sure way is to delete the whole disk and force full garbage collection.
According to this individual, the assertion that data can be retrieved after a disk has been overwritten, even with just one pass of zeros, is largely just a theory.
There aren't any actual proofs of this. Anywhere. Think about that. Someone would have published by now.
Seems to me it could only be on hard disks and rewritable CD's and USB sticks would be safe from that.
Heard anything about prior data on USB sticks?