The Millennium franchise, based on the wildly popular book series by Stieg Larsson and David Lagercrantz, is back in theaters. The films thus far have been somewhat difficult to keep up with, with an entire Swedish-prouduced trilogy made in 2009 and an unrelated American adaptation of The Girl with the Dragon Tattoo arriving in 2011. The newest U.S. entry, The Girl in the Spider's Web, is both a sequel and reboot to the 2011 film, and it's introducing some new concepts to the series, including a dangerous computer program known as FireWall. But is FireWall a real program, or was it just invented for dramatic purposes? Minor spoilers ahead.
FireWall is not real, and that's a good thing, because the computer program as it exists in the movie is incredibly dangerous. It also plays a highly important role in the film, as it's the main instigator of the plot. In the movie, FireWall is a computer program invented by a former NSA employee named Frans Balder. The program is able to access the launch codes for the entire world's arsenal of nuclear weapons, meaning that whoever controls the program has the potential to destroy the world. Believing his creation to be too dangerous to exist, Balder enlists the help of the franchise heroine — expert hacker Lisbeth Salander, played here for the first time by Claire Foy — to destroy FireWall and make sure no one can ever use it to steal nuclear codes and, you know, blow up the world.
It's a good thing there is no FireWall in real life, because nuclear proliferation remains one of the greatest threats facing the world's population. There are currently at least nine nations possessing nuclear weapons (the United States, Russia, China, France, the United Kingdom, India, Pakistan, North Korea, and Israel — though the latter nation doesn't acknowledge that fact, according to the Washington Post), and all of them have their own unique systems in place that would launch them in the event of a nuclear war.
In the U.S., nuclear weapons can be launched via codes that are provided to the president and associated with goofy names like "nuclear football" and "nuclear biscuit" that somewhat undermine their seriousness. The nuclear football is actually a briefcase containing the nuclear launch codes and instructions that is always held by an aide in the president's company while the president is traveling. It gives the Commander-in-Chief the ability to launch a nuclear attack when away from a stationary command center where such a request would normally be made. The football is used in conjunction with the nuclear biscuit, according to Fortune, a plastic card with a unique identification code that the president is supposed to always have in their possession. A new "biscuit" is created every four months with different codes, according to Business Insider. After a launch order is given, the president must prove their identity with the biscuit, and the Secretary of Defense then must confirm that the president really gave the order and not an imposter.
Given the security measures in place for the American codes alone, it's hard to imagine a program that could not only obtain the U.S. codes, but also the codes of the eight other nuclear powers. That's what makes FireWall so scary, and also what keeps it firmly in the world of fiction.