Cryptanalytical techniques are often called attacks, which gives rise to the picturesque jargon surrounding this otherwise rather
technical and complicated branch of mathematics:

  • known (chosen) plaintext attack
  • known (chosen) ciphertext attack
  • adaptively chosen plaintext attack
  • etc...

And speaking of picturesque, let's not forget that cryptanalysis is often termed a black hat activity...except when our side is doing it,
in which case it becomes white hat. For instance the cryptanalysis of the Enigma coding machine carried out by Alan Turing and
others during World War II was undoubtedly white hat...
(And if you're asking yourself: "Enigma, isn't it the machine that valiant american sailors captured on a Nazi submarine?" the answer
is: "No". That was a Hollywood movie, and a historical lie. The Brits made almost all of it by themselves. Sorry, folks.)