[5537] in cryptography@c2.net mail archive
Re: 'Spy cameras may have been installed in photocopiers all over theworld'
daemon@ATHENA.MIT.EDU (Matt Blaze)
Sun Sep 5 15:53:08 1999
To: Ross Anderson <Ross.Anderson@cl.cam.ac.uk>
Cc: Zombie Cow <waste@zor.hut.fi>, eucrypto@fitug.de,
ukcrypto@maillist.ox.ac.uk, cryptography@c2.net
In-reply-to: Your message of "Sun, 05 Sep 1999 12:02:23 BST."
<E11Na42-00085s-00@heaton.cl.cam.ac.uk>
Date: Sun, 05 Sep 1999 13:10:21 -0400
From: Matt Blaze <mab@crypto.com>
>As we only had a small copier, I fairly frequently went to the copy
>shop in Kensington High Street. I noticed that whenever I ordered n
>copies of a document, the thing would flash n+1 times. `Nice one', I
>thought, and kept my mouth shut
I'm no expert on the photocopier technology of the early 80's, and I
certainly have no idea what kind of copier your Kensington copy shop used,
but what you describe is perfectly normal behavior in at least some
copiers. I remember noticing an extra flash every time I copied
something on a Bell Labs copier (that happened to located just down the
hall from a secure "vault"). My paranoia juices pumping at full capacity,
I opened the copier late one night when no one was looking, expecting to
find the cache of "escrowed" copied documents, or perhaps a microfilm camera.
What I did find was a copy of the copier manual, which explained
that an extra flash is measures density and makes exposure adjustments
before each copy run. I have no idea how many models of copier do this.
Now when I see an extra flash from a copy machine I apply Occam's
Razor and ignore it. Of course, Occam might give us a rather
different explanation when there are Iraqi and Iranian arms buyers down
the street, as you point out.
-matt
