The machinery was secret, but the lessons learned quietly trickled out. Newman, Flowers and Turing couldn't talk about what they did at Bletchley, but they made substantial contributions to the development of computers in the post-war years.

And thus also the contribution of people like Kilburn, featured rather sadly in a BBC documentary and particularly relevant here, with many in a similar boat.

And still being used until quite late on :-) we sold a lot of countries surplus enigma machines