On the first day of the war, the British ship Telconia, under the benefit of darkness, approached the German coast, dropped anchor where it knew it would find German submarine communications cables, pulled up the cables, and cut them. In this way, the British forced the Germans to use radio transmission, which was much more easily intercepted, or to use submarine cables owned by other nations, such as Sweden or the United States, which in both cases passed through England. This was the case, for example, with the famous Zimmermann Telegram addressed to the Mexican government, intended to induce the Mexicans to attack the United States. This telegram was intercepted by the British, which instead convinced the reticent Americans of German hostility. From a cryptographic standpoint, the information that the British intercepted and decoded the German message was kept secret by the British, and the Germans were led to believe that the “leak” was actually due to a leak from the Mexican side. This false assumption persisted until the Second World War, when the Germans, confident that their codes were still “unbreakable”, created a more ingenious, but not entirely innovative, version: the Enigma machine.
