Swedish Cryptology I [Scanning Our Past]

This month’s article is the first of two which describe cryptographic inventions and codebreaking in Sweden from early times up until 1945. In the first half of the 20th century, Sweden created for itself a strong presence in the world of cryptography. Whether this process was the consequence of actions by individuals or followed from the general industrial and cultural advancements is arguable. Perhaps, both played a role. From the 16th century onward, manual systems of enciphering, such as substitution ciphers and codes, were used by the court, the army, and other official organizations. In this article, though, we will take as a starting point the design of what appears to be the world’s first ciphering machine in 1786, finishing the presentation with the outbreak of the Second World War (WW2) in 1939. In a sequel, we will describe the successes and failures of Swedish Sigint, cryptanalysis, and defensive cryptography during WW2.