Prying eyes on your PC secrets !

[Krrish]

"To start or not to start ". That was the question I had whenever I thought about this thread. I am already a DV addict. I consider everyone here as a family. So I decided that I will start this thread. Now I got a wonderfull reason to start this thread. This was the front page of "The New Indian Express", Friday 30 December 2005, the leading newspaper of India. The headline was about the terrorist attack in Bangalore, the intellect city of India. But look at the bottom news. Its a dream come true for me. EDIT : I resized the image so that it doesnt affect the template of this page. The link to previous image is given. Also click on the image to get the news zoomed in : And the page 5: When we completed the project we went to different news reporters to publish it. They said NO. They dont understand what it was. Then we stopped going behind them. After that they started coming behind us. What a contradiction ? Now in the front page of a national daily !!!!!!!!!!!!!!!!!!! Doing a reality check..... Thanks to ImageShack for Free Image Hosting The story of our project is a long one. I can tell it if you are interested. Those who want to know more on the subject Tempest and Van eck phreaking, use the following links The Complete, Unofficial TEMPEST Information Page Van Eck Phreaking TEMPEST If you want to delete this thread, plz do it. If you want to move it to Extended discussion, that will be a nice idea. Now I am ready to discuss about something that I really know. This is a rarely discussed thread. If it is discussed then it consist of so many myths and wrong data as I have found in the internet. One more thing. I know that " THIS IS NOT A GREAT THING ". But for India, it was a surprise and it will boost us to find a Good Job in electronics field.

[MSG]

That is awesome!!! Front page, man! I read something about tempest a while ago, someone made a program that streamed audio to any nearby radio that could receive AM transmissions. If the victims were using a non-standard resolution or refresh/frame rate on a custom monitor would this device be able to recognize the signal?

[Krrish]

Originally posted by pOOp I read something about tempest a while ago, someone made a program that streamed audio to any nearby radio that could receive AM transmissions. Yes. The motivation to begin our project was that program. It was shipped with a linux magazine and I successfully installed and used that program. The program is Tempest for Eliza I was doing some experiments in programming with linux at that time. Tempest for Eliza is a Program that uses your computer monitor to send out AM radio signals. You can then hear computer generated music in your radio. You want some basic knowledge in linux to get it working. The first part of the program is to send a MIDI tune as electromagnetic waves in to a near by radio. We got a range of 50 m for that. The place I live is almost noise free. To get the second part in to working, we needed some tweaking. The second part is to send mp3s as AM waves. I think there was some error in the code for sampling of mp3. We corrected it and made it working. The mp3 had very low range. The link to the webpage of Tempest for Eliza was a treasure for us. It revealed a whole new world. There are so many links given in that page. We were studying electromagnetic field theory at that time and got really interested after visiting the The Complete, Unofficial TEMPEST Information Page. The rest is a long story. If any one has any problem while experimenting with Tempest for Eliza, I am sure that I can help you. If you are a real techie, Read the pdf given in this page. It is really an encyclopedia. There was a full description of how to make a van eck phreaking object in http://gbppr.trighost.org/. I am sure that it is still there. But I cant access it now. The website is forbidden for people in INDIA ( may be ASIA )

[Krrish]

Originally posted by pOOp If the victims were using a non-standard resolution or refresh/frame rate on a custom monitor would this device be able to recognize the signal? If we have a broad band antenna, no problem with the resolution or refresh rate. We have a tuner block in the demodulator circuit to tune in to specific frequency. But it will take some time initially. We used a log periodic antenna for our project. In the range of 100 - 1000 MHz Also more than one computer will be present in the same room. You can also make all those systems matching by having the same reolution and refresh rate for all those. But still we have no problem. The two monitors or video card cant be placed in exactly same position. So we can make use of the property of Directivity of antennas. Another fact is that the clock signals generated by CPU or video card to drive monitor is temperature dependent. So there will be some difference in the exact resolution and refresh rate of two monitors. Since it has no sync signals asociated with it, we are supplying it manually. So the signal matching the sync will be displayed and the other will roll off. If you are interested, I can provide a block diagram. But no Circuit diagram.

[icedawg]

Fascinating. Are CRTs the only type of monitor susceptible to this type of eavesdropping, or are LCDs as well?

[Krrish]

Originally posted by icedawg Fascinating. Are CRTs the only type of monitor susceptible to this type of eavesdropping, or are LCDs as well? MYTH #1 Only CRT monitors emit radiations that can be captured and reconstructed. As given in the unofficial tempest site: LCD displays on laptops eliminate the risks of TEMPEST attacks. Maybe, maybe not. The technology behind LCD monitors versus typical CRT monitors may somewhat reduce the risk, but I wouldn't bet my life on it. There have been anecdotal accounts of noisy laptop screens being partially displayed on TVs. If laptops were emanation proof, I seriously doubt there would be TEMPEST standard portables on the market. [/b] Sadly the term Van Eck Phreaking is often connected with monitor. From our studies, we understood that the primary source of radiation is Video card and not monitor. When we directed our antenna towards the video card ( the cpu ) instead of monitor, we got double range. The monitor only acts as a catalyst. .................... .................... I posted the same thread in a couple of other forum to get more exposure and some challenging questions. More discussions are going on there. http://www.thinkdigit.com/forum/viewtopic.php?t=35428 http://forums.vsociety.net/topic/7338.0