Re: Secure passwords?

"Hairy One Kenobi" <abuse@[127.0.0.1]> wrote in
news:8Fcnf.4522$zt1.656@xxxxxxxxxxxxxxxxxxxx:

> "nemo_outis" <abc@xxxxxxx> wrote in message
> news:Xns97286406A4BCFabcxyzcom@xxxxxxxxxxxxxxxxxx
>> "Hairy One Kenobi" <abuse@[127.0.0.1]> wrote in
>> news:Qxxmf.480$q4.124@xxxxxxxxxxxxxxxxxxxx:
>>
>> > The real reason is even more simple - faster boxes tend to radiate
>> > more and, since most of that is the computer equivilent of
>> > "tum-te-tum, hurry up and type something", the interferance will
>> > help to conceal unshielded keyboard and screen signals (which is
>> > all one is interested in).
>>
>> The putative effects of interference are frequently overestimated. It
>> is electronic child's play to filter interference and even, given the
>> enormous redundancy in many signals, to extract information many
>> decibels *below* the noise floor.
>
> "Child's play"? Gotta have a cite for that one.. admittedly, I'm
> assuming that the box is somewhere close to the CRT and keyboard.



Here's one example of a "canned solution" extracting signals from noise
using FFT integration. This particular device concentrates on audio but
the processes are quite general and apply to virtually all signal
processing. Hell, these things are now pretty standard - they last were
cutting edge when I read about them in Aviation Week in the 60s!

http://www.baudline.com/manual/process.html



>> >> Some interesting speculations (and with Tempest we are all
>> >> speculating to some degree).
>> >
>> > Not necessarily (although I certainly don't claim to be an
>> > expert!). Even the most unobservant person will be able to compare
>> > and contrast a bit of Tempested kit that they are using day-in,
>> > day-out with the equivilent standard kit. Last I looked, the UK
>> > classification for Tempest was the same level as the canteen menu
>> > at the local Job Centre.
>>
>> I disagree. Few have access to Tempest kit to make observations,
>> other than illustrations in manufacturers' brochures (which disclose
>> little other than the obvious). A few may work with such devices but
>> almost always in an environment where physical security confines
>> their interactions solely to use, not investigation. Virtually no one
>> except those related to the manufacturer or maintenance crews has a
>> chance to get "under the hood." Not for nothing are even the
>> standards themselves classified.
>
> Few != None
>
> Some of us may well have used such equipment for years (hint, hint)
>
> See above for the trivial classification level, at least here in the
> UK.


Those who know do not speak; those who speak do not know :-)

You may, as you hint, have some level of access to these things. But
whether that translates into understanding either the defensive and
offensive capabilities of emsec as applied to computers is not clear -
and likely to remain that way, I guess. Use != understand But even if
you do understand, your understanding is of (nearly) zero value to anyone
else if you are constrained from communicating it.



> Saying that, it's perfectly possible that thr /are/
> higher-classification documents floating around - after all, a UK
> Defence Screen sequence (classified as Confidential) was shown on the
> BBC's Horizon programme in full. Similarly, some sonar kit fitted to
> Trafalgar class subs was classified as Secret - in regards to where on
> the boat it was placed, and its specification - but was clearly listed
> in both Jane's and other publications.
>
> Wouldn't surprise me overmuch if the exact performance characteristics
> were stil classified - basically for what they tell you about the
> sensors being employed. Simply estimating the weight of Tempested kit
> should tell you how much steel has been involved in the shielding, let
> alone simply buying something and taking it apart!


Oh, the performance of most such machines is fairly clearly defined: they
conform to some level of NATO standard AMSG 788 (& 719, 720, 784, etc. as
well as corresponding national standards, including the simple BSI zone
model). However, the contents of those standards are classified!

But even if the standards were right in front of me, I don't want just a
cookbook recipe (standards are generally heavy on "shalls" but silent on
the underlying rationale). No, I want an understanding of what could be
deployed against me, with what capabilities, at what cost, by which
agencies. And none of that is available.

Any fool (well, any technologically competent fool) can shield from emsec
if he just throws money at the problem. RFI/EMI shielding is not exotic
by any means; it's well-travelled technological ground. No, the trick is
knowing whether, say, 50 dB suppression is sufficient (for a particular
class of threat) or whether 100 dB is necessary. Big difference in cost
(including the secondary problems that arise re ventilation & cooling,
etc. and issues regarding usability). Moreover, even technologically
competent fools don't just build and pray - they test and do QA on their
designs. That means very expensive test equipment, equipment that is
prohibitively expensive for onesy-twosy do-it-yourself projects.

Regards,

PS And so far we have largely confined our discussions to passive
emsec. There is a whole other dimension of active emsec where equipment
to be scanned is "bathed" in EM signals which the computer (or whatever
is under investigation) modulates.

.

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