The Lorenz cipher is a type of encryption used by the German military during World War II. It was designed to secure high-level communications and was more complex than the earlier Enigma machine. The Lorenz cipher utilized a series of rotating wheels and a binary code to encrypt messages, making it difficult for enemies to decode. To break the Lorenz cipher, Allied cryptanalysts, including Bill Tutte, developed advanced techniques and used early computers. Their efforts were crucial in deciphering German communications, contributing significantly to the success of the Allied forces in the war.