Perdition said:
data recovery techniques these days means that you'd have to rewrite
the entire harddrive over 7 times (7 levels of erasure being DOD
standard) to ensure some security, and even then it won't go over parts
which are flagged as defective. The information has to be erased to the
highest military standard meaning rewrites aren't acceptable, it has to
be destroyed. Whether the entire motherboard is destroyed as well is
irrevelant, the computer must never be used again
Here is some public info on drive destruction. This should
give you some idea of what level of secret is compatible with
what erasure/destruction method.
http://www.rcmp-grc.gc.ca/tsb/pubs/it_sec/g2-003_e.pdf
This is not military standard, but would be sufficient for
most civilian uses. This is a disk drive that does encryption
at the drive level. Obviously, there are all sorts of questions
about "back doors" and whether the NSA could crack it, but for
a situation where your computer is stolen during a break and
enter, this should be sufficient.
http://www.seagate.com/newsinfo/newsroom/success/D2g42.html
http://www.seagate.com/content/docs/pdf/marketing/PO-Momentus-FDE.pdf
I would feel safer, if the architecture looked like this.
Being able to specify the algorithm and the key, should give
you more control.
programmable ordinary
motherboard ---- encryption ------ hard
engine drive
|
|
removable key and
algorithm
Another thing you could consider using, is solid state drives
(so-called RAM disks or solid state disks). It would be easier
to engineer destruction of the media (the RAM) by electrical
means, than to destroy a platter. (Simply switching off the
power may not be sufficient to meet your needs.) These are not
very convenient, in terms of form factor, and this one is tiny
in capacity. Larger versions are rack-mountable.
http://www.cenatek.com/store/category.cfm?Category=9
A third option, is for your computers to be diskless. The
computer boots from a network disk. This is good for installations
in an office building, where the server room is locked up, and
the computers in the office area are subject to possible theft.
This should bring back fond memories of IBM mainframes, 3278
terminals, or X terminals plus server architecture.
Paul