I waited all day trying to forget this comment but I can't.
Sorry to be so blunt but this is an incredibly stupid statement.
What earthly good is knowing your enemies plans if you can do nothing about them?
In terms of the "Battle of Britain" it was only the RAF ( your Spitfire pilots and observer crews ) with a great deal of support from radar and the British command and control systems (Fighter Command) which prevented an invasion. Bletchly added very little to this particular battle and this particular battle was, arguably, the turning point in the war.