> Years ago Mr. Hoover claimed the Bureau had a sample of the typeface
> of virtually every typewriter manufactured.
This is a marker of oppressive regimes. Similar databases were in Soviet
Russia, Romania, East Germany, and other such areas.
See here:
http://en.wikipedia.org/wiki/Typewriter#Forensic_identification
> Since the keys, and later
> the balls, were individually crafted by tool and die workers, there
> was always some difference between the machines. However, with the
> advent of the personal computer and desktop laser printers, the use of
> typewriters dropped substantially. From a law enforcement standpoint,
> it was a bit of a blow. However, if all laser printers are now going
> to be coded, then they will be as easy to trace as the typewriters
> were.
Even without this, laser printers show very minuscule irregularities due
to unique patterns like wear of the drum or inaccuracies of the mechanical
gears, producing "banding" on the page.
> A final thought. Could not the machine's signature be either altered
> or eliminated by modifying the circuitry - or is it going to be
> another black box affair?
Of course it could. However, the right way is not in modification of the
circuitry but in patching the printer's firmware. Oppressive measures can
be removed this way. Typical case is hacking of firmwares of DVD players,
where the affected code typically deals with playing of DVDs from other
zones (the RPC2 "protection"), or with checking of media types in game
consoles so burned DVDs can be played. (In case of DVD players/drives,
often the way is to reflash their firmware with version for Australia/NZ,
where players with region coding enforcement are deemed illegal.)
http://en.wikipedia.org/wiki/DVD_region_code
For more information about printer dot patterns, see here:
http://en.wikipedia.org/wiki/DVD_region_code
There is a detailed site dealing with the problematics at the Electronics
Frontiers Foundation site:
http://www.eff.org/issues/printers
http://w2.eff.org/Privacy/printers/docucolor/
A list of printers tested for the presence of the tracking dots is here:
http://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots
Enjoy :)
Received on Sat Mar 02 2024 - 00:57:26 CST