And all the mathematical breakthroughs needed to crack Enigma and make it tractable to the primitive computers of the day were made by the Poles anyway, which was conveniently airbrushed from history.
Bletchley Park acted as central clearinghouse for intercepted ciphertexts, distributing decryptions with elaborate care to keep the Germans from knowing Enigma had been cracked. Late in the war, they built an electronic gadget called Colossus to decrypt traffic from a much more difficult version of Enigma.