Briefly defined as the 'art or practice of preparing or reading messages in a form intended to prevent their being read by those not privy to secrets of the form and the science of devising methods and means for this
,' by Webster's Lexicon.
Until the early 20th century the somewhat occluded field was dominated by theologians, spies and lurking courtiers - an obscurant
's patchwork of the odd mathematical
formulae, antique word and letter tables, unique and inspired clockwork
, and often pseudo- scientific literature.
While enormously entertaining for historians of the secret society
, the dark arts
were of little or no interest to common folk; ciphers attracting the odd criminal agent, a subset of the diplomatic corps to various nations and an odd-ball mix of scientists and hobbyists.
Two world wars
dramatically changed the significance of the field forever- proving what some analysts and engineers had been saying for some time- information could be treated and manipulated 'as physical
,' that it had to be considered another 'front' of the conflict, that its collection in every obscure and occluded form had to be taken very seriously. The mobilization & armament of data
did not cease there- as the Cold War
spread first through Europe and then the rest of the world; encryption of private communications
became a staple expenditure of both sides.