On Wed, 11 Oct 2006 00:38:03 -0500, "Ken Maltby"
wrote:


You know how an IC gives off heat in relation to how
hard it is working, ("constant current" is a myth) heat is
only one part of the electromagnetic spectrum.

No, constant current is a fact. The IC draws constant
current in many MP3 players and does not substantially
change it's heat output unless entirely turned off or put to
sleep which is an entirely separate mode of player
operation, not momentary in use like with a CPU.


Switching
devices certainly produce as much "noise" when they
operate as analog devices, more in most cases.

We may have a mic on shielded cable running to a constant
current chip that digitizes. It's spitting out digits when
there's no noise as well as when there is. Yes there may be
noise, but it may not vary as with the old analog, and
certainly not as noisey as something more obvious- a
transmitter signal.

We have
devices that can detect very, very low wattage signals.

That may be useful if you have an object in your hand, but
remember the unknown context of this thread, and that they
can't be constantly false detecting cell phones, beepers,
etc, providing the cell phone isn't recording off-grid which
is a whole 'nuther issue.

"kony" wrote in message
...
On Wed, 11 Oct 2006 00:38:03 -0500, "Ken Maltby"
wrote:


You know how an IC gives off heat in relation to how
hard it is working, ("constant current" is a myth) heat is
only one part of the electromagnetic spectrum.

No, constant current is a fact. The IC draws constant
current in many MP3 players and does not substantially
change it's heat output unless entirely turned off or put to
sleep which is an entirely separate mode of player
operation, not momentary in use like with a CPU.


No, contsant current isn't a fact. When an IC sends outputs the signals on
the traces are switching and unless the same data is flowing you will see
different currents depending on what data is bieng sent and what was sent
before. Resistance can also change.


---Matthew Hicks

"kony" wrote in message
...
On Wed, 11 Oct 2006 00:38:03 -0500, "Ken Maltby"
wrote:


You know how an IC gives off heat in relation to how
hard it is working, ("constant current" is a myth) heat is
only one part of the electromagnetic spectrum.

No, constant current is a fact. The IC draws constant
current in many MP3 players and does not substantially
change it's heat output unless entirely turned off or put to
sleep which is an entirely separate mode of player
operation, not momentary in use like with a CPU.


Switching
devices certainly produce as much "noise" when they
operate as analog devices, more in most cases.

We may have a mic on shielded cable running to a constant
current chip that digitizes. It's spitting out digits when
there's no noise as well as when there is. Yes there may be
noise, but it may not vary as with the old analog, and
certainly not as noisey as something more obvious- a
transmitter signal.

We have
devices that can detect very, very low wattage signals.

That may be useful if you have an object in your hand, but
remember the unknown context of this thread, and that they
can't be constantly false detecting cell phones, beepers,
etc, providing the cell phone isn't recording off-grid which
is a whole 'nuther issue.


Normally people entering rooms have to pass through
doorways. I would think any "open mike" that responds to
the pattern should be considered a threat.

But look, you can believe what you want, your world can
be a much simpler place, if you don't delve into these issues.

Luck;
Ken

On Wed, 11 Oct 2006 16:49:05 -0500, "Matthew Hicks"
wrote:


"kony" wrote in message
.. .
On Wed, 11 Oct 2006 00:38:03 -0500, "Ken Maltby"
wrote:


You know how an IC gives off heat in relation to how
hard it is working, ("constant current" is a myth) heat is
only one part of the electromagnetic spectrum.

No, constant current is a fact. The IC draws constant
current in many MP3 players and does not substantially
change it's heat output unless entirely turned off or put to
sleep which is an entirely separate mode of player
operation, not momentary in use like with a CPU.


No, contsant current isn't a fact. When an IC sends outputs the signals on
the traces are switching and unless the same data is flowing you will see
different currents depending on what data is bieng sent and what was sent
before. Resistance can also change.


The signals are fairly constant, encoded bits regardless of
whether there's silence or not. My argument is not whether
the mere presences of signals can be deteced, but rather
there is a significant enough difference in signal to detect
with sound input versus silence (in the room).

Claiming you will see different currents based on the data
is easy with the gear open and measurement by wire. Trying
to find whether there is an unknown device present or not is
not quite same situation.

On Wed, 11 Oct 2006 17:28:13 -0500, "Ken Maltby"
wrote:

That may be useful if you have an object in your hand, but
remember the unknown context of this thread, and that they
can't be constantly false detecting cell phones, beepers,
etc, providing the cell phone isn't recording off-grid which
is a whole 'nuther issue.


Normally people entering rooms have to pass through
doorways. I would think any "open mike" that responds to
the pattern should be considered a threat.


Sure, but we haven't established that it really will be
detectable based on a pattern of sound. Presuming it will
because some other type of device can be detected isn't
reliable.


But look, you can believe what you want, your world can
be a much simpler place, if you don't delve into these issues.

This is a fairly generic non-applicable comment. We could
as easily consider the opposite, that you can believe what
you want and your world can be a much more paranoid place if
you don't delve into the specifics- but either way we cannot
assume detection without any evidence of same type device
BEING detected in an applicable scenario. While a doorway
detector could be more easily implemented than some, it's
also not going to detect a device turned off at the time.

We'll have to consider the specifics of a digital recorder,
and perhaps even more significantly one that might be chosen
to be harder to detect if it were to be used for a stealthy
purpose.

Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.storage Jamie t wrote:

Arno Wagner wrote:


In comp.sys.ibm.pc.hardware.storage Joey wrote:


Suppose someone visited your office or home and tried to make a voice
recording using a hidden recorder.


If they used a older-style dictation machine based on tape then you
could detect the electromagnetic transmissions from the dictation
machine when it was recording.


But how would you detect if someone was secretly recording with an MP3
player that recorded to flash memory?


Is there some transmission which could be detected?
Perhaps some low power ultra high frequency from chip refresh cycles?


Not really. You could maybe detect that it was turned on with
an RF scanner. But if it is low power enough (most MP3 players
are, since they are optimised for that) and well shielded, you
would likely get nothing in today's RF polluted environment.
In addition the attacker may just add some more shielding to be
sure. I think you can basically forget about this, unless you
can take the devices away from people.

Arno


i have seen a device used by an electrical instructor at a trade
school. he does not like any Cell, recorders or electronic devices
active while in his class. this device will buzz and vibrate in his
pocket as he walks around the class, he can walk right up to the
student that has something on.. it works by detecting a variation
of known R.F. frequencies that helps him decide on an LCD screen of
the device what it could be, and then it has wide band detection of
any R.F. generation.. as you know, most devices do generate some
R.F. of some freq.. i've seen it in use and its on the
market... all i can say is by his words, "it works very good"


That sounds like BS to me. Of course cellphones are very easy to
detect that way, and I expect that is what he is showing off. Forget
about non-woreless devices. They have several orders of magnitude
less RF emanations. This guy is likely demonstrating with
cellphones and then claiming he can detect the other things
without ever demonstrating.

Arno

maybe you should step out of the dark and into the real world.
have you ever use a service monitor to scan a wide spectrum of
frequencies?
i can tell you that wide band receivers on a mini board exist and
are very sensitive to external R.F. when your standing beside the person
with in 3 feet of them.
most devices these day's involve embedded processes which also uses
R.F. clock devices. it would take a very high priced unit with proper
casing and shielding to reduce the emissions low enough for this device
to not detect it. most consumer electronics is very sloppy in the area.
in fact, there has been cases where cheaply made devices that xfer lets
say audio information in a digital format causes their internal osc's to
be unstable enough when voice is passing through the mic/pre'amp
circuits, that some one with a high gain FM receiver can detect clear
enough audio from a distance before it even gets encoded digitally for
final destination.
the average joe wouldn't even think of this let alone attempt to
waste their time in trying it how ever, there are people out there that
spend a lot of time investigating consumer devices just for the purpose
of simple wireless taps and detection of use.




--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

In comp.sys.ibm.pc.hardware.storage Jamie t wrote:
Arno Wagner wrote:

In comp.sys.ibm.pc.hardware.storage Jamie t wrote:

Arno Wagner wrote:


In comp.sys.ibm.pc.hardware.storage Joey wrote:


Suppose someone visited your office or home and tried to make a voice
recording using a hidden recorder.


If they used a older-style dictation machine based on tape then you
could detect the electromagnetic transmissions from the dictation
machine when it was recording.


But how would you detect if someone was secretly recording with an MP3
player that recorded to flash memory?


Is there some transmission which could be detected?
Perhaps some low power ultra high frequency from chip refresh cycles?


Not really. You could maybe detect that it was turned on with
an RF scanner. But if it is low power enough (most MP3 players
are, since they are optimised for that) and well shielded, you
would likely get nothing in today's RF polluted environment.
In addition the attacker may just add some more shielding to be
sure. I think you can basically forget about this, unless you
can take the devices away from people.

Arno


i have seen a device used by an electrical instructor at a trade
school. he does not like any Cell, recorders or electronic devices
active while in his class. this device will buzz and vibrate in his
pocket as he walks around the class, he can walk right up to the
student that has something on.. it works by detecting a variation
of known R.F. frequencies that helps him decide on an LCD screen of
the device what it could be, and then it has wide band detection of
any R.F. generation.. as you know, most devices do generate some
R.F. of some freq.. i've seen it in use and its on the
market... all i can say is by his words, "it works very good"


That sounds like BS to me. Of course cellphones are very easy to
detect that way, and I expect that is what he is showing off. Forget
about non-woreless devices. They have several orders of magnitude
less RF emanations. This guy is likely demonstrating with
cellphones and then claiming he can detect the other things
without ever demonstrating.

Arno

maybe you should step out of the dark and into the real world.
have you ever use a service monitor to scan a wide spectrum of
frequencies?

I have used a spectrum analyser. I admit I am not an EMI expert.
However cellphone detection is far simpler than detection of other
devices....

i can tell you that wide band receivers on a mini board exist and
are very sensitive to external R.F. when your standing beside the person
with in 3 feet of them.
most devices these day's involve embedded processes which also uses
R.F. clock devices. it would take a very high priced unit with proper
casing and shielding to reduce the emissions low enough for this device
to not detect it. most consumer electronics is very sloppy in the area.
in fact, there has been cases where cheaply made devices that xfer lets
say audio information in a digital format causes their internal osc's to
be unstable enough when voice is passing through the mic/pre'amp
circuits, that some one with a high gain FM receiver can detect clear
enough audio from a distance before it even gets encoded digitally for
final destination.
the average joe wouldn't even think of this let alone attempt to
waste their time in trying it how ever, there are people out there that
spend a lot of time investigating consumer devices just for the purpose
of simple wireless taps and detection of use.

Oh, I know. But I was pointing out that the guy described does not need
to have what he claimed. And in addition, how do you separate, e.g., the
crystal in a high-powerd pocket calculator from the one in the MP3
recorder? Detecting RF energy is not that difficult. It becomes
difficult if you have a lot of background noise or need an identification
in addition.

Arno

On 11 Oct 2006, Dana wrote:


"Ken Maltby" wrote in message
...

"Joey" wrote in message
...
On 10 Oct 2006, kony wrote:

On Tue, 10 Oct 2006 15:51:51 +0100, Joey
wrote:


You say, "search them physically"? I have to tell you that I
don;'t work in the sort of environment where that kind of
behaviour is considered acceptable!


Then the only practical alternative remaining is to have
them consent to and go through a metal detector, and of
course it has to be actively manned to discriminate a
potential recorder from some other device, object, etc.

If you find what might be an MP player, you won't be able to
determine if it's recording, rather than playing, or if
recording off the radio. Unless MP3 players become
illegal devices, or at least clearly posted as banned on
private premises, you can't justify a search or seizure
either (depending on laws in your locale). If private
property, the other party may still refuse a search and
seizure attempt.

Even scanning for such a device's radiated energy at
entrance to an area, that wouldn't prevent them from turning
on the device later. Unless you have the expectation that
you can seize such equipment, you should follow the same
guidelines you should have otherwise- not saying anything of
importance in the presence of someone who can't be trusted
not to repeat, reproduce, etc., in any way.

Ultimately going to such extra lengths will tend to make
people suspect you have something to hide and put your
activities under more scrutiny.


Thanks Kony. So the MP3 recorder is essentially undetectable
during its operation. OK. Thanks.

Maybe that explains why I can't find any follow-on products for
tape recorder detection while many of the the older devices are
no longer available.

It should not come as a surprise, that security concerns that
deal in high level technological detection devices, don't
advertise to the general public that much. Search harder.


I hinted at that a couple of days ago.
It has been amusing watching some of the replies from some of the
people here.




You man there actually is something which will detect MP3 recorders?

On 11 Oct 2006, Aly wrote:

Joey wrote in message
...
[...]

Sorry for my rather unhelpful reply, I'm having one of my moments
where I only talk to microcontrollers.


No problems.

Seriously though. There's very little in world that's so
important. I've worked with people that would *record* meetings
thinking they were of vital importance when in actual truth, no one
could care less.

I guess it would just cause people to be more careful about what
they say. I'm unable to view those videos you've supplied as this
is a development machine without any clutter on it.

eBay could be a good place to buy such things though. All sorts of
stuff comes out of the AsiaPac.


This is to document something quite serious.

"Joey" wrote in message
...
On 11 Oct 2006, Dana wrote:


"Ken Maltby" wrote in message
...

"Joey" wrote in message
...
On 10 Oct 2006, kony wrote:

On Tue, 10 Oct 2006 15:51:51 +0100, Joey
wrote:


You say, "search them physically"? I have to tell you that I
don;'t work in the sort of environment where that kind of
behaviour is considered acceptable!


Then the only practical alternative remaining is to have
them consent to and go through a metal detector, and of
course it has to be actively manned to discriminate a
potential recorder from some other device, object, etc.

If you find what might be an MP player, you won't be able to
determine if it's recording, rather than playing, or if
recording off the radio. Unless MP3 players become
illegal devices, or at least clearly posted as banned on
private premises, you can't justify a search or seizure
either (depending on laws in your locale). If private
property, the other party may still refuse a search and
seizure attempt.

Even scanning for such a device's radiated energy at
entrance to an area, that wouldn't prevent them from turning
on the device later. Unless you have the expectation that
you can seize such equipment, you should follow the same
guidelines you should have otherwise- not saying anything of
importance in the presence of someone who can't be trusted
not to repeat, reproduce, etc., in any way.

Ultimately going to such extra lengths will tend to make
people suspect you have something to hide and put your
activities under more scrutiny.


Thanks Kony. So the MP3 recorder is essentially undetectable
during its operation. OK. Thanks.

Maybe that explains why I can't find any follow-on products for
tape recorder detection while many of the the older devices are
no longer available.

It should not come as a surprise, that security concerns that
deal in high level technological detection devices, don't
advertise to the general public that much. Search harder.


I hinted at that a couple of days ago.
It has been amusing watching some of the replies from some of the
people here.




You man there actually is something which will detect MP3 recorders?

There are devices that can detect when electronic devices are being used.
There are devices that can be made that can detect almost any known material
If said mp3 player is made of that material it can be detected.