backscatter

Noun

• The deflection of particles and/or radiation through angles greater than 90 degrees to the original direction of travel.
• The particles and/or radiation deflected in this manner.
• A portion of the energy of electromagnetic radiation such as a laser or radio waves that is scattered back in the direction of the source of radiation by an obscurant.
• The sending of IP packets to essentially random addresses in response to incoming packets that have a spoofed origin.

Verb

• To scatter particles and/or radiation back to the direction from which they come.