How detect if MP3 player is recording in your room? [OT]
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. |
How detect if MP3 player is recording in your room? [OT]
"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 |
How detect if MP3 player is recording in your room? [OT]
"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 |
How detect if MP3 player is recording in your room? [OT]
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. |
How detect if MP3 player is recording in your room? [OT]
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. |
How detect if MP3 player is recording in your room? [OT]
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 |
How detect if MP3 player is recording in your room? [OT]
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 |
How detect if MP3 player is recording in your room? [OT]
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? |
How detect if MP3 player is recording in your room? [OT]
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. |
How detect if MP3 player is recording in your room? [OT]
"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. |
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