The Black Chambers: 1500–1776

Abstract

The period from 1500 through the middle of the 18th century saw the creation of modern nations and city-states. It also saw increased use of codes and ciphers in diplomacy, the military, and commerce. The nomenclator, a marriage of the code and cipher is a product of this period. This period also saw the creation of a cipher that would remain “unbreakable” for 350 years, the polyalphabetic substitution cipher. This chapter traces the history of the Black Chambers, those organizations created by the newly formed nations to break the codes and ciphers of their neighbors, and it describes the nomenclator and the evolution of the polyalphabetic substitution cipher known as the Vigenère cipher.