By registering with us, you'll be able to discuss, share and private message with other members of our community.

  1. Welcome to the 12ozProphet Forum...
    You are currently logged out and viewing our forum as a guest which only allows limited access to our discussions, photos and other forum features. If you are a 12ozProphet Member please login to get the full experience.

    If you are not a 12ozProphet Member, please take a moment to register to gain full access to our website and all of its features. As a 12ozProphet Member you will be able to post comments, start discussions, communicate privately with other members and access members-only content. Registration is fast, simple and free, so join today and be a part of the largest and longest running Graffiti, Art, Style & Culture forum online.

    Please note, if you are a 12ozProphet Member and are locked out of your account, you can recover your account using the 'lost password' link in the login form. If you no longer have access to the email you registered with, please email us at [email protected] and we'll help you recover your account. Welcome to the 12ozProphet Forum (and don't forget to follow @12ozprophet in Instagram)!

/the typical "add a capacitor on the line and see what happens" syndrome/

Discussion in 'Channel Zero' started by BROWNer, Nov 13, 2002.

  1. BROWNer

    BROWNer Guest



    Across the darkened street, a windowless van is parked. Inside, an antenna is pointed out through a fiberglass panel. It's aimed at an office window on the third floor. As the CEO works on a word processing document, outlining his strategy for a hostile take-over of a competitor, he never knows what appears on his monitor is being captured, displayed, and recorded in the van below.

    "...In the past, the acknowledgement of an intelligence asset has usually meant it had become obsolete. Security experts tell POPULAR MECHANICS that the unanticipated growth of Internet traffic may be more than Echelon can handle. And, NSA has in fact confirmed its computers were shut down for three days last year.

    Some believe the recent candor is because NSA is shifting to a new, more tightly focused espionage strategy, using a ground-based technology code-named Tempest. The underlying theory is that electronic circuits create " compromising emanations." Not to be confused with interference, these are subtle but measurable changes in surrounding systems - comparable to the dip in line voltage that occurs when the light in your refrigerator goes on as you open the door.

    NSA is said to have perfected Tempest to the point at which it can reconstruct the images that appear on a video display or TV screen."read this entire article(mainly echelon)


    NSA was capturing and deciphering tempest emissions during the cuban missile crisis and possibly earlier. you can bet the shit they have now is bulletproof tough.

    What is TEMPEST?

    TEMPEST is a U.S. government code word that identifies a classified set of standards for limiting electric or electromagnetic radiation emanations from electronic equipment. Microchips, monitors, printers, and all electronic devices emit radiation through the air or through conductors (such as wiring or water pipes). An example is using a kitchen appliance while watching television. The static on your TV screen is emanation caused interference.

    During the 1950's, the government became concerned that emanations could be captured and then reconstructed. Obviously, the emanations from a blender aren't important, but emanations from an electric encryption device would be. If the emanations were recorded, interpreted, and then played back on a similar device, it would be extremely easy to reveal the content of an encrypted message. Research showed it was possible to capture emanations from a distance, and as a response, the TEMPEST program was started.

    The purpose of the program was to introduce standards that would reduce the chances of "leakage" from devices used to process, transmit, or store sensitive information. TEMPEST computers and peripherals (printers, scanners, tape drives, mice, etc.) are used by government agencies and contractors to protect data from emanations monitoring. This is typically done by shielding the device (or sometimes a room or entire building) with copper or other conductive materials.



    an unclassified general description of TEMPEST that was presented at an Air Force security seminar in 1987:

    [i]What is TEMPEST

    Bruce C. Gabrielson, PhD
    Security Engineering Services
    5005 Bayside Road
    Chesapeake Beach, MD 20732

    What is TEMPEST

    If you ask most people what TEMPEST means, they will probably quote the standard definition:

    TEMPEST is an unclassified short name referring to investigations and studies of compromising emanations, conducted or radiated, on complete equipment.

    While TEMPEST is certainty this, it is in reality the study of emissions in a much broader category, the study and detailed examination of communications theory. TEMPEST emissions are basically the result of inadvertent telemetry systems formed naturally by electronic devices and propagated via natural physical elements (antennas or wires) to the outside world. The efficiency of this inadvertent TEMPEST telemetry system to transmit signals through natural means is in reality the weakness of the equipment to protect its secure information.

    Where Theory and Test Investigations Meet

    Since the communications channel in a TEMPEST system is not intended to convey information, the signals (compromising emanations) are not optimized for best reception. Therefore, a TEMPEST engineer must be familiar with other engineering disciplines such as information theory, complex modulation theory, and transmission line theory if he is to fully understand the scope and depth of the emanation problem.

    Being able to unscramble a complex signal is simply a matter of understanding the probabilities of what each signal might represent for a particular type of data stream. In other words, a signal developed from an ASCII data source looks different than one originating from a CCITT data source. Also, signals transmitted in return to zero format look different then those sent non-return to zero.

    Modulation also is a problem. Signals can modulate on a carrier or appear as a baseband source. Amplitude modulated signals are the easiest to identify, and also the simplest to demodulate. Even with a trained eye however, since background noise sources are usually high, and since Gaussian noise distributions can sometimes look like signals, simply assuming that a detected signal is a compromising emanation can lead to massive overkill in a redesign effort. Also, since in TEMPEST systems, signals often modulate a harmonic of a noise source, these emanations can appear at nearly any frequency in the spectrum. The bottom line is that in the majority of cases, an engineering approach that disregards communication theory, and simply addresses redesign through trial and error test techniques, is both expensive and difficult to achieve in a reasonable time period.

    Where Theory and Design Meet

    Far too many modern TEMPEST engineers use "run and gun" type redesign approaches to fix emanation problems they find. This is the typical "add a capacitor on the line and see what happens" syndrome. The approach usually results in long redesign efforts, and often simply shifts the problem to another frequency or location, which is then found at a later date resulting in additional problems. What they don't understand is that signals radiate because transmission line theory tells us that if the signal channel's source and load impedance don't match, which they never do at all harmonics of a signal, then standing waves are created and some energy escapes to the outside world. Re-tuning the transmission line simply changes its characteristic impedance, and the signal will still be present, just at some other frequency.

    As most TEMPEST design engineers will agree, fixing a problem before it appears is by far the most desirable approach. However, TEMPEST redesigns normally are intended to fix someone else's problems "after the fact". Here is where design and theory really merge. If the TEMPEST engineer understands the theory, plus if he is familiar with the limitations and capabilities of rf design techniques, he can usually provide a problem solution consistent with overall program needs. He can first find the problem, then generate a fix specific to the problem that won't simply move it to some other location, and finally, insure the problem stays fixed by maintaining constant quality control over the fix implemented.

    A New Definition

    Probably the best approach to explaining what TEMPEST is all about is to re-define the term as follows. Note that this is a personal definition, not anything officially used.

    TEMPEST is the application of reverse communication theory to the design and test of complete equipment or systems which process and/or transmits secure information.

    While this definition isn't formatted in the normal jargon of the defense industry, it does cover the critical concerns that face the TEMPEST engineer during his daily activities. [/i]


    + [url=http://www.tscm.com/TSCM101tempest.html]TEMPEST 101[/url]
  2. --zeSto--

    --zeSto-- Veteran Member

    Joined: Jul 12, 2000 Messages: 6,979 Likes Received: 2
    be afraid, be very afraid <---- that's my caption line !
  3. Fabo 2

    Fabo 2 Member

    Joined: Mar 20, 2002 Messages: 345 Likes Received: 2
    Oi BROWNer

    I know this is channel zero, but do you ever post anything remotely to do with graffiti?
  4. --zeSto--

    --zeSto-- Veteran Member

    Joined: Jul 12, 2000 Messages: 6,979 Likes Received: 2
    ^^ what? you dont see the connection ?
  5. Pistol

    Pistol Dirty Dozen Crew

    Joined: Jul 12, 2001 Messages: 19,363 Likes Received: 299
    I thought this was going to be about Flex Capacitor's and time travel.
  6. BROWNer

    BROWNer Guest


    i don't really give a shit about graffiti outside
    my city's scene. plus there are a million kids posting
    graf shit already, why would i bother?
    graffiti is mad boring.
  7. Grandola

    Grandola Senior Member

    Joined: Jul 16, 2002 Messages: 1,773 Likes Received: 0

    simple schematics.
  8. Dirty_habiT

    Dirty_habiT Administrator

    Joined: Mar 8, 2001 Messages: 18,135 Likes Received: 82
    I just woke up and this is a bit too much for me. Schematics confuse the hell out of me.
  9. mikro137

    mikro137 Guest

    flux dude! cmon dude!
  10. FourOneTwo

    FourOneTwo Member

    Joined: May 10, 2002 Messages: 924 Likes Received: 0
    Is anyone else terriby confused....because I definetly wasnt going to read all that shit.
  11. Fabo 2

    Fabo 2 Member

    Joined: Mar 20, 2002 Messages: 345 Likes Received: 2
  12. ctrl+alt+del

    ctrl+alt+del Guest

  13. funkhandlerest
  14. zen

    zen New Jack

    Joined: Sep 20, 2001 Messages: 0 Likes Received: 0
    Whoa they can read ANYTHING. I feel very safe.
  15. When

    When 12oz Loyalist

    Joined: May 4, 2000 Messages: 10,294 Likes Received: 3
    havent you posted this before?