Electronic protection

In electronic warfare, electronic protection measures can be used to defend against electronic attack. They may be passive, such as shielding one's own equipment, using highly directional antennas, or other techniques. Active defenses are often called electronic counter-countermeasures, and include making one's signal hard to detect and thus attack

Passive protection

Basic techniques include electromagnetic shielding, proper grounding, use of highly directional antennas, and visual deception (i.e., camouflaging the equipment, especially the antennas).

Active protection

Active measures make the signal difficult to detect, and changes its properties frequently so the attack must constantly change. Methods include low-probability-of-intercept, rapidly changing frequencies (i.e., frequency agility) or transmitting/receiving locations (e.g., multistatic techniques, mixing the signal with noise (i.e., spread-spectrum technology), and a wide range of other methods.