A COLOSSAL SECRET
Your country is at war, and you start picking up directional radio signals that sound like nothing you’ve ever heard before. The enemy is highly mechanized, makes use of the latest technology, and has a record of using complex codes and ciphers in its transmissions. This is something new, however. Instead of the dots and dashes of the Morse code you’re used to intercepting, this sounds like a harsh wailing.
These days, we’d probably equate the sound with a 56K modem, but back in the 1940s, it was known as teleprinter code. Nazi high command, not content with the “unbreakable” Enigma cipher it used to spread orders among its companies and brigades, was also using a machine for higher-level communications called the Lorenz SZ that British codebreakers had never seen, and would not see until the end of World War II. Despite this, they were able to deduce how it worked, and crack the encipherment.
This is the story of a country house in England full of mathematicians, crossword enthusiasts, the occasional genius, and a man from the postal service more used to creating automated telephone exchanges. Together, they read German military communications and shortened WWII by up to four years, saved possibly millions of lives, and created Colossus, the first programmable electronic computer, in the process.
his is a complicated story, and we’ve had to leave bits out, but bear with us, there’s still a lot of backstory. The tale of how the British, Alan Turing in particular, cracked Enigma, opening up Nazi communications, and making it possible to anticipate their every move is already fairly well known, but it has some parallels with the decryption of the Lorenz machine that can’t be ignored. The Nazis had mechanized the sending of secret messages, so a mechanized approach was needed for reading them. Lorenz had similar weaknesses to the Enigma, especially if you could
