In a world in which security now means electronic privacy and 128-plus-bit encryption technologies as much as it means a deadbolt on the door of your suburban home, Hollywood has re-imagined historical matters of national security as the province of seminal geeks, crytographers and math geniuses. Witness the probably overrated “A Beautiful Mind” which looks too awful for me to bring myself to see, or the upcoming “Windtalkers,” directed by John Woo, which tells the tale of Native American human code bearers in World War II. Last weekend I saw “Enigma,” the British version of this same conceit — which features a highly qualified cast but unfortunately amounts to little.