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Radiated Method to Generate Disinformation Jamming to Prevent Electromagnetic Eavesdropping Disclosure Number: IPCOM000213620D
Publication Date: 2011-Dec-22
Document File: 3 page(s) / 73K

Publishing Venue

The Prior Art Database


Disclosed is a methodology for creating a vectored disinformation signal to thwart eaves dropping onto a laptop.

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Radiated Method to Generate Disinformation Jamming to Prevent Electromagnetic Eavesdropping

Problem is radiation from computer screens whose information can be determined by detection demodulation display and recording. Known as Van Eck radiation, it is lessened by the use of LCD displays rather than CRTs. However, it has been demonstrated that the drive currents along the cable to the LCD display has enough power, even at low levels, that it can be "pulled" out of the noise floor, detected, and demodulated to form a display. It has been shown that the signal, with proper detection equipment, can be demodulated at a distance of about 200 ft. This detection poses a security concern for those wishing to keep vital information confidential.

    The new approach is not to attempt to fully shield the information from the potential hacker but to provide generated disinformation or scrambled random data at the same level, or greater, driven by the exact same clock as the vital information. However, if the antenna pattern is different between the vital and random information, it is possible to separate these signals from each other and detect the vital information. But, if the shape of the random/disinformation antenna pattern masks the shape of the vital information pattern, detection will be difficult. Of course, any added signal level must be within the maximum emission level (military-tempest level) as required. Masking can also be improved by ensuring that the masking signal is slightly above the maximum level generated by the vital information.

    Ideally, an electromagnetic emission would be low enough so as not to be detected at all from an operating laptop. However, with sophisticated preamplifiers and preselectors, many signals can be "pulled" out of the noise floor. Signals that are driven by the clock source, itself, that is coherent with the actual display d...