Emission Security (EMSEC)
Definition - What does Emission Security (EMSEC) mean?
Emission security may also be called emanation security.
Techopedia explains Emission Security (EMSEC)
More specific issues addressed by EMSEC include crosstalk from twisted pair cables, leakage from radio frequency signals, and anything else related to the interception of transmitted communications. Those studying emission or emanation security might study various kinds of "bugs" or eavesdropping equipment in order to understand how systems can be secured.