Tempest

Tempest, temp’pest, n. lit. a portion of time, a season, then weather, bad weather; wind rushing with great velocity, usually with rain or snow; a violent storm ; any violent commotion. [L. tempestas, a season. tempest—tempus, time]

Tempest was the name of a classified (secret) U.S. government project to study  the susceptibility of some computer and telecommunications devices to emit electromagnetic radiation (EMR) in a manner that can be used to reconstruct intelligible data. Tempest's name is believed to have been a code name used during development by the U. S. government in the late 1960s, but at a somewhat later stage, it became an acronym for Telecommunications Electronics Material Protected from Emanating Spurious Transmissions.
https://searchsecurity.techtarget.com/definition/Tempest

 

In 2011, a group of young students discovered a new meaning of Tempest that had remained hidden for 200 years. This is their story ...