I mean, permanently write to the OS. Somebody might bust in and change
it in RAM/etc. But, reboot, clean again.. (I figure..)
The NSA had one of their contractors develop the SE-Linux stuff for
Linux. It's open source, free.. (Security Enhanced Linux..) Anybody can
use it..
There's also the idea of not loading programs into predictable areas of
memory. I think Windows also can do that..
However, I'm sure any complex system has errors in the code that will be
found over time, and probably agencies like the NSA spend huge sums on
finding them - and not talking about them. Using them.
Another way to protect is something like tripwire (etc. etc. etc. etc.)
on Linux. Maybe there are similar things for Windows.. (maybe not..)
It does a checksum of all the files on the system. Store the data on
something like a DVD, say.. Then do regular checks. If something is
changed, you know.. More sure than something like anti-virus.. Probably
best to run off a DVD/etc. too..
There's also the issue of simply driving a van up on the street, shining
a laser beam at a window, and getting the sound vibrations off it. Hear
everything going on inside..
Then, brain waves. Both EMF and on the ethereal plane. For that, simply
line a football helmet with aluminum foil, two layers. <joke - it
probably won't work on the ethereal..>
The British were getting radio emissions from computer monitors/etc. in
the London USSR embassy to know what was coming across the screens. The
US government came up - IIRC - with the "tempest" standard. I have a
couple of NEC multisync monitors that were modified by some company for
that, and have farraday cages around the guts. I think it just lines the
inside of the case, and the monitors aren't changed otherwise.. You can
see it through the grills. I think cost me $5 each. (I don't use them,
just collector items to me..) It seems to me the monitors say "tempest"
on them.. Top secret contractors/defense/etc. have to use them. I'm
sure any company that doesn't want their secrets revealed does the same
with various equipment.
http://en.wikipedia.org/wiki/Tempest_%28codename%29
Public research
In 1985, Wim van Eck published the first unclassified technical analysis
of the security risks of emanations from computer monitors. This paper
caused some consternation in the security community, which had previously
believed that such monitoring was a highly sophisticated attack available
only to governments; van Eck successfully eavesdropped on a real system,
at a range of hundreds of metres, using just $15 worth of equipment plus
a television set.
In consequence of this research such emanations are sometimes called "van
Eck radiation," and the eavesdropping technique van Eck phreaking,
although government researchers were already aware of the danger, as Bell
Labs noted this vulnerability to secure teleprinter communications during
World War II and was able to produce 75% of the plaintext being processed
in a secure facility from a distance of 80 feet.[9] Additionally the NSA
published Tempest Fundamentals, NSA-82-89, NACSIM 5000, National Security
Agency (Classified) on February 1, 1982. In addition, the van Eck
technique was successfully demonstrated to non-TEMPEST personnel in Korea
during the Korean War in the 1950s.[citation needed]