Tempest?

Tempest?

Post by GWNapi » Sun, 08 Jun 1997 04:00:00



Can anyone tell me what  a tempest attack is?

 
 
 

Tempest?

Post by Galactu » Sun, 08 Jun 1997 04:00:00


-----BEGIN PGP SIGNED MESSAGE-----



> Can anyone tell me what  a tempest attack is?

TEMPEST is a standard for electromagnetic shielding for computer
equipment. It was created in response to the fact that information can
be read from computer radiation (e.g., from a CRT) at quite a distance
and with little effort.  Needless to say, encryption doesn't do much
good if the cleartext is available this way.  The typical home
computer WOULD fail ALL of the TEMPEST standards by a long shot. So,
if you are doing anything illegal, don't expect PGP or any other
encryption program to save you. The government could just set up a
monitoring van outside your home and read everything that you are
doing on your computer.

"Tempest attack" basically means "an attack with means that could
be defended against if the target shields his computer according
to TEMPEST."

- --
To find out more about PGP, send mail with HELP PGP in the SUBJECT line to me.


Anonymity and privacy site: http://www.stack.nl/~galactus/remailers/

-----BEGIN PGP SIGNATURE-----
Version: 2.6.3i
Charset: noconv

iQCVAgUBM5nYVzyeOyxBaho1AQFOGAP+OqkoguquPfLIniy+8WDUipJjLeqj+LNZ
hdWWvPByMoSg+wT9OsHXN+lZ6UBZ4G3PAZrqpy9ylGWq859fMuRCMrbFzzYxRJSn
087flcLP2PXNRUTqba6CkzoywSK+Pe0jT77A9hl9Lp9QWaIHP6STloR/E1S7yiX5
CVtQOK/G+jQ=
=B318
-----END PGP SIGNATURE-----

 
 
 

Tempest?

Post by Mike Nayl » Sun, 08 Jun 1997 04:00:00



>Can anyone tell me what a tempest attack is?

Briefly, it means to monitor radio-frequency emissions from a device and
interpret them in order to learn what is going on inside the device.
--

Play Five by Five Poker at http://www.serve.com/games/
 
 
 

Tempest?

Post by Ian Lynag » Tue, 17 Jun 1997 04:00:00


Once upon a time, in the land of comp.security.pgp.discuss, J. D. Cooley
eloquently composed:

Quote:>They can see everything (in color, BTW) that is happening on your computer
>screen.

But my passphrase never goes onto the screen, so how
can they get it?

Anyway, can't I just turn the screen off?

TTFN
Ian
--

http://www.veryComputer.com/~balchen/igloo/

Too err is human. To really*things up you need a computer.

 
 
 

Tempest?

Post by Wim Lew » Tue, 17 Jun 1997 04:00:00




Quote:>Once upon a time, in the land of comp.security.pgp.discuss, J. D. Cooley
>eloquently composed:
>>They can see everything (in color, BTW) that is happening on your computer
>>screen.

>But my passphrase never goes onto the screen, so how
>can they get it?

Most descriptions of TEMPEST attacks talk about reading stuff from
the screen, but long serial cables also radiate. IIRC (one of) the
first demonstrated attacks was on a line-printer connected to its
host by a serial cable. Your keyboard, incidentally, talks to your
CPU over a long, probably poorly shielded serial line.

--

    PGP 0x27F772C1: 0C 0D 10 D5 FC 73 D1 35  26 46 42 9E DC 6E 0A 88

 
 
 

Tempest?

Post by Ian Lynag » Wed, 18 Jun 1997 04:00:00


Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
eloquently composed:

Quote:>Your keyboard, incidentally, talks to your
>CPU over a long, probably poorly shielded serial line.

What is the best (cheapest, easiest) way to
stop that?

ISTR that my PCMCIA network card had a 1*1*2cm ish
cuboid which clipped around the cable. Inside
were a couple of magnets. Does this provide
satisfactory shielding? Are there any docs on this
on the web?

TTYL
Ian
--

http://www.sn.no/~balchen/igloo/

Computers will never replace human stupidity.

 
 
 

Tempest?

Post by Jack Winga » Wed, 18 Jun 1997 04:00:00



>Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
>eloquently composed:
>>Your keyboard, incidentally, talks to your
>>CPU over a long, probably poorly shielded serial line.

>What is the best (cheapest, easiest) way to
>stop that?

>ISTR that my PCMCIA network card had a 1*1*2cm ish
>cuboid which clipped around the cable. Inside
>were a couple of magnets. Does this provide
>satisfactory shielding? Are there any docs on this
>on the web?

>TTYL
>Ian

take a look at:

http://www.eskimo.com/~joelm/tempest.html

should tell you all you need to know.

JW

 
 
 

Tempest?

Post by David Sternligh » Thu, 19 Jun 1997 04:00:00



> <!--

> >Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
> >eloquently composed:
> >>Your keyboard, incidentally, talks to your
> >>CPU over a long, probably poorly shielded serial line.

> I think one good benefit of having Tempest protection is being able to
> put a radio near your computer and listen to the AM band without
> having to listen to the awful QRM.

An interesting historical footnote: Back in 1953 when I was working on
the Whirlwind I computer at MIT, one bit of the accumulator (the
arithmetic register) was connected to an MIT telephone line. When your
program was running you could call the number and if you were familiar
with a program, tell what it was doing or if it was stuck in a loop.
Programs made distinctive "sounds" as they ran--an experienced user
could often tell not only if "his" program was running (or if a
particular very long top priority job that pre-empted getting on the
machine was still running) but what section of a long program the
computer was in.

In those days (when magnetic core memory was first being invented at
MIT), the computer was often down. You could tell that as well, and save
yourself a trip to the Barta building on your bicycle at 3 a.m. (or at
least know to phone before coming in) if you were scheduled to run a low
priority job then.

David

 
 
 

Tempest?

Post by Nicholas Bo » Thu, 19 Jun 1997 04:00:00





>>Once upon a time, in the land of comp.security.pgp.discuss, J. D. Cooley
>>eloquently composed:
>>>They can see everything (in color, BTW) that is happening on your computer
>>>screen.

>>But my passphrase never goes onto the screen, so how
>>can they get it?

>Most descriptions of TEMPEST attacks talk about reading stuff from
>the screen, but long serial cables also radiate. IIRC (one of) the
>first demonstrated attacks was on a line-printer connected to its
>host by a serial cable. Your keyboard, incidentally, talks to your
>CPU over a long, probably poorly shielded serial line.

Can anyone provide (or identify a source for) information on what sort
of shielding is sufficient to defeat attacks of these kinds?  It would
be nice to know whether aluminium cooking foil has any effect, for
example, before I build a small hutch of quarter inch steel plates.
--
Nicholas Bohm

[Please disregard numerals in my email address;
they are to frustrate junk email.]

 
 
 

Tempest?

Post by Rebecca and Rowla » Fri, 20 Jun 1997 04:00:00


-----BEGIN PGP SIGNED MESSAGE-----


> Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
> eloquently composed:
> >Your keyboard, incidentally, talks to your
> >CPU over a long, probably poorly shielded serial line.

> What is the best (cheapest, easiest) way to
> stop that?

Good screening - you've been pointed at a web page.  I suspect that a
decent Faraday cage would be enough - well earthed conductive mesh
should do the job.  *Everything* needs to be enclosed in a well-earthed
screen.  Thick metal is no better than thin metal; multiple layers can
help, but shouldn't be needed; conductivity is important, so kitchen
foil is better than steel sheet (although the right kind of steel will
block the magnetic component of EM radiation as well as the electrical
component; the most effective solution is probably copper sheet
enclosing mu-metal sheet.  This would be very expensive and wreak havoc
on the cooling air-flow).

It's more sensible to use commercial EMI screening products - you can
buy stick-on foil for cases and conductive braid to wrap around cables
etc.

It's very important that you find out how to use these things
effectively - if you get it wrong, you'll have no way of knowing about
it unless you've got access to specialist measuring equipment.

Quote:

> ISTR that my PCMCIA network card had a 1*1*2cm ish
> cuboid which clipped around the cable. Inside
> were a couple of magnets. Does this provide
> satisfactory shielding?

No - are you sure it contained magnets?  Ferrite beads, maybe, but
magnets would be unusual.  This box, if it contains ferrite beads, adds
a little inductance to the cable to slow down fast signals a little and
reduce ringing etc.  It's not too uncommon to see this kind of bodge.
However, they are also used sometimes to reduce electromagnetic
emissions to meet regulations - the reduction is usually quite small
(about 8dB) - enough to meet the regulations, but not enough to stop
someone reading your data.

Rowland.

- --
Take the animal out of the line below to construct my email address:

PGP public key available on email request
Key fingerprint = F5 60 5E AE F5 6F 2C 0B  81 8F 33 19 52 27 76 7F
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2, by FileCrypt 1.0

iQCVAwUBM6lOZ8Wt5C+mgLidAQGvQwP/dnDJEvwJat7eIpQbnuafste/CrgCQhY3
A+SBp+rRkQwoWxEpKvwfA+cRYKHyeH0Tn4yXgy/rtAoHLie9iD9/Ih6BCSHROt5y
dkNJaBmOExM6Q6vOXfv4ExOsivhrKbUj1JM1LKwpvEcGJbCbhCjzceTVfp2WTDnV
MjoIZ7py+os=
=a7M1
-----END PGP SIGNATURE-----

 
 
 

Tempest?

Post by Ian Lynag » Sat, 21 Jun 1997 04:00:00


Once upon a time, in the land of comp.security.pgp.discuss, Rebecca and
Rowland eloquently composed:


>> Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
>> eloquently composed:
>> >Your keyboard, incidentally, talks to your
>> >CPU over a long, probably poorly shielded serial line.

>> What is the best (cheapest, easiest) way to
>> stop that?

>decent Faraday cage would be enough - well earthed conductive mesh

Doesn't sound easy or cheap...

Quote:

>It's more sensible to use commercial EMI screening products - you can
>buy stick-on foil for cases and conductive braid to wrap around cables
>etc.

...and that sounds expensive too, as well as
unportable :(

Is it possible to blast out random EM radiation to
hide the real EMR? Would this be harmful?

Quote:>> ISTR that my PCMCIA network card had a 1*1*2cm ish
>> cuboid which clipped around the cable. Inside
>> were a couple of magnets. Does this provide
>> satisfactory shielding?

>No - are you sure it contained magnets?

I'm not sure, no. ISTR a faint magnetic attraction
though.

--

http://www.sn.no/~balchen/igloo/

Windows has detected a random error. This occurs every once in a while.
Please wait.

 
 
 

Tempest?

Post by Rebecca and Rowla » Sun, 22 Jun 1997 04:00:00


-----BEGIN PGP SIGNED MESSAGE-----


> Once upon a time, in the land of comp.security.pgp.discuss, Rebecca and
> Rowland eloquently composed:


> >> Once upon a time, in the land of comp.security.pgp.discuss, Wim Lewis
> >> eloquently composed:
> >> >Your keyboard, incidentally, talks to your
> >> >CPU over a long, probably poorly shielded serial line.

> >> What is the best (cheapest, easiest) way to
> >> stop that?

> >decent Faraday cage would be enough - well earthed conductive mesh

> Doesn't sound easy or cheap...

> >It's more sensible to use commercial EMI screening products - you can
> >buy stick-on foil for cases and conductive braid to wrap around cables
> >etc.

> ...and that sounds expensive too, as well as
> unportable :(

The foil's not especially cheap, but doesn't affect portability.  I
don't know of a convenient way of dealing with cables.  The *big*
problem is ensuring that the mesh over the front of your monitor is
effective...

Quote:

> Is it possible to blast out random EM radiation to
> hide the real EMR? Would this be harmful?

Yes, it is possible, but you'd need measuring equipment to ensure that
you were jamming the right frequencies.  I doubt that it'd be harmful,
but it would*up any other electronics in the area - you need to
kick out roughly 10 times the power of the signal you're jamming for
this to be effective.

Quote:> >> ISTR that my PCMCIA network card had a 1*1*2cm ish
> >> cuboid which clipped around the cable. Inside
> >> were a couple of magnets. Does this provide
> >> satisfactory shielding?

> >No - are you sure it contained magnets?

> I'm not sure, no. ISTR a faint magnetic attraction
> though.

Could be a bit of magnetism acquired when the ferrite beads were made.

Rowland.

- --
Take the animal out of the line below to construct my email address:

PGP public key available on email request
Key fingerprint = F5 60 5E AE F5 6F 2C 0B  81 8F 33 19 52 27 76 7F
-----BEGIN PGP SIGNATURE-----
Version: 2.6.2, by FileCrypt 1.0

iQCVAwUBM6rgHcWt5C+mgLidAQFl3wP7BTXVKQZBPWRrWEFOjHoju8ulnv4hxUpw
G+Vafx1nSdCWZL7ZHPdSrQRI7yGqhv4XlNuAhgkqOsaR8HrZMEZBF9KVTNKuGsA1
zteKfHBBVPbeaGCN4/pl23frIE1TtEYU63rUeiiA+6TOggpRvtdNKYWybaQeS+2E
ZfHpe6PL78E=
=tmIX
-----END PGP SIGNATURE-----

 
 
 

1. Tempest PC`s: are inside a TEMPEST-PC standard components?

Hi,

are inside a Tempest PC standard components? Is only the
case/cage responsible for shielding the Van Eck emissions
(of corse, also a tempested mouse, video and keyboard is
needed)?

I am asking that, because we intend to buy Tempest PC`s
and are wondering about upgrading them some years later
ourselves. Are we going to de-tempest them by installing
standard components?
(sending the PC`s back to factory for upgrading and
recertificating them could turn out to be extremly
expensive).

Thank`s for any tip!

Glen

2. Q: Universal vs trained model for entropy coding.

3. Laserjet 4 (tempest model 3400)

4. CM-SOFT

5. Psion5-Outlook printing problem

6. (MAC!) Tempest clone

7. Test iss-base V2.0 for 90 days - NOW

8. Amiga Tempest

9. Qbert, Tempest, GridIron

10. Tempest

11. Tempest door "Assassin" - where can it be found?

12. TEMPEST-type game!