Video signal level (colour intensity) and effectiveness of electromagnetic infiltration

Nowadays, when we have a strong presence of computers in our everyday lives the protection of electronically processed information using digital machines becomes very important. It is related to accidental formation of electromagnetic fields which distinctive features are intrinsically linked to the nature of processed information. Although many protective measures are taken - from technical to organisational - this phenomenon still poses a great threat. Therefore, methods supporting information protection against the so-called electromagnetic infiltration are still being developed. In addition, these methods would support security of data processing and perhaps replace some of the currently used solutions characterised by high costs of implementation, or a small degree of ergonomics. Conducted research deals both with an analogue VGA and digital DVI standards. The article presents the results of the research concerning possibilities of manipulating the level of video signal (black colour intensity) and its influence on the quality of displayed images, that is, on the effectiveness of electromagnetic infiltration