Security Paranoia

Sometimes, we wonder that does IT security will ever end ? Can we say that "we have done enough" and we feel secured ? Obvious answer is "NO". It is never enough. Whatever we do, we will find need for more. That’s the hard reality of  Security Vs. Hacker world.  Unfortunately, hackers are smarter then we think.

IT security have no limits. I know a lot of techniques what are implemented in different locations, for hide the important information, beginning from a simple key locked door to fingerprint identification and so?.
But the ultimate technique for information thief is really painful.

There are two very interesting technologies to see your display from distance.

1. Optical Time-Domain Eavesdropping Risks of CRT Displays
The overall light emitted by a commonly used cathode-ray tube computer monitor is a broadband information carrier that transmits via light-intensity modulation the low-pass filtered video signal. It is feasible to reconstruct screen contents from this information channel, even if the eavesdropper cannot position a sensor within a direct line-of-sight to the target display surface and receives the light only after diffuse reflection, for instance from an office wall

2. Electromagnetic Radiation from Video Display Units
It is possible in some cases to obtain information on the signals used inside the equipment when the radiation is picked up and the received signals are decoded. Especially in the case of digital equipment this possibility constitutes a problem, because remote reconstruction of signals inside the equipment may enable reconstruction of the data the equipment is processing.
If no preventive measures are taken, eavesdropping on a video display unit is possible at several hundreds of meters distance, using only a normal black-and-white TV receiver, a directional antenna and an antenna amplifier. It is even possible to pick up information from some types of video display units at a distance of over 1 kilometer. If more sophisticated receiving and decoding equipment is used, the maximum distance can be much greater.

Sometimes, we wonder that does IT security will ever end ? Can we say that "we have done enough" and we feel secured ? Obvious answer is "NO". It is never enough. Whatever we do, we will find need for more. That’s the hard reality of  Security Vs. Hacker world.  Unfortunately, hackers are smarter then we think.

IT security have no limits. I know a lot of techniques what are implemented in different locations, for hide the important information, beginning from a simple key locked door to fingerprint identification and so?.
But the ultimate technique for information thief is really painful.

There are two very interesting technologies to see your display from distance.

1. Optical Time-Domain Eavesdropping Risks of CRT Displays
The overall light emitted by a commonly used cathode-ray tube computer monitor is a broadband information carrier that transmits via light-intensity modulation the low-pass filtered video signal. It is feasible to reconstruct screen contents from this information channel, even if the eavesdropper cannot position a sensor within a direct line-of-sight to the target display surface and receives the light only after diffuse reflection, for instance from an office wall

2. Electromagnetic Radiation from Video Display Units
It is possible in some cases to obtain information on the signals used inside the equipment when the radiation is picked up and the received signals are decoded. Especially in the case of digital equipment this possibility constitutes a problem, because remote reconstruction of signals inside the equipment may enable reconstruction of the data the equipment is processing.
If no preventive measures are taken, eavesdropping on a video display unit is possible at several hundreds of meters distance, using only a normal black-and-white TV receiver, a directional antenna and an antenna amplifier. It is even possible to pick up information from some types of video display units at a distance of over 1 kilometer. If more sophisticated receiving and decoding equipment is used, the maximum distance can be much greater.