We explored aspects of cryptology, drawing on historical examples to explain concepts such as the frequency principle, where common letters give clues to codebreaking. We also looked into transposition ciphers, the spatial placement of letters to hide meaning. This extended to mono-alphabetic transposition ciphers used as far back as the days of Julius Caesar, where letters transposed hid the message. And poly-alphabetic substitution ciphers, where wheels with alpha-numeric sequences added layers to the substitution, complicating decryption.
Cryptologists brought to their task powerful intellects. They included the elite among linguists, historians, artists and mathematicians. Some had mysterious intuitive powers that could not be easily explained to others.
Often scholars have missed the role this intelligence played in statecraft because it isn’t “bombs bursting in air”. Napoleon, for instance, is lionised by many, including Carl von Clausewitz, in On War. Yet after a series of battlefield successes, his enemies matched him, the winning differential being espionage and cryptography.
Napoleon lost in Moscow, on the Iberian Peninsula, and at Waterloo, having dismissed the value of intercepting and decoding enemy messages. Clausewitz played down the usefulness of intelligence, echoing Napoleon’s approach, despite the latter’s defeats from 1812, which can be attributed to ignorance of the enemy as well as hubris. Armchair strategists to this day still miss the significance of espionage and deception to diplomatic and military success.
Electricity, telegraphy, wireless radios, Morse code and submarine cables, which arrived in the 19th and early 20th centuries, amplified the powers of cryptographers and other Sigint practitioners.
The cabinet noir or black chamber (where secret messages were accessed, copied, deciphered and translated) gave negotiators a secret advantage that was often decisive. In the modern era, the headquarters of America’s National Security Agency is housed in a building designed to look like a black chamber.