High Quality Content by WIKIPEDIA articles! TEMPEST is a codename referring to investigations and studies of compromising emanations (CE). Compromising emanations are defined as unintentional intelligence-bearing signals which, if intercepted and analyzed, may disclose the information transmitted, received, handled, or otherwise processed by any information-processing equipment. Compromising emanations consist of electrical, mechanical, or acoustical energy intentionally or by mishap unintentionally emitted by any number of sources within equipment/systems which process national security information. This energy may relate to the original encrypted message, or information being processed, in such a way that it can lead to recovery of the plaintext.