|Stories||WarGames Annoyances Kelly D. Chien 2008-07-19|
recently picked up the movie "WarGames" on the $5 shelf at Wal*Mart. I figured for that price it was worth the investment. I hadn't seen the movie in probably been 20 years, and hey, Matthew Broderick is cute! Well, Ally Sheedy is cuter, but that's besides the point. It's still just a fun flick to watch.
ne thing that greatly disturbs me though is Hollywood's continuing perplexing misinformation on some technical issues that are expressed rather strongly in this movie. The first is the WOPR's cracking of the launch codes, and the second is the display of the launch codes. I'll mention that i have a 20 year background in computer security and a 35 year background in audiovisual display technology, so i have some small understanding of these issues.
he WOPR spends a large portion of the movie trying to guess the new launch codes and we see this on the large display screens as random characters flashing by. Every now and then the WOPR "finds one" of the characters. This event is illustrated by that character remaining steady on the screen and an announcement that another number has been found. Very dramatic, keeps you on the edge of your seat and takes your breath away as more and more of the numbers are matched. It's also incredibly bogus and stupid.
've used computer security systems. I've hacked computer security systems. Heck, i've created computer security systems. I can tell you for a fact that not one computer system in use anywhere, much less in a high security situation such as controlling nuclear missiles, will EVER tell you that you've got one of the digits right. Never. Why would it? Either you know the access code or you're not supposed to get in. If you know the access code then you don't need to have the system tell you that you're getting closer. Either you got it right and you get in, or you got it wrong because you made a typo and you do it again correctly and you get in. If you're not supposed to get in then the system simply will not help you. In fact, almost all security systems will disconnect you and prevent further attempts if you get the code wrong after a few tries. None of them will let you keep trying millions of codes indefinitely.
ut, ok ... for drama's sake lets say that NORAD contracted a bunch of computer idiots to create that security system and it did in fact let an attacker know when each digit was matched. How long would it take to crack such a system and log in? In the movie it takes about 10 minutes. Is this realistic? Could any automated attack really crack a 10 digit random code that fast? Is this believable? Nope, not in the slightest could i possibly believe it would be done in 10 minutes. It would actually take less than a half a minute as it was shown in the movie and probably about a hundredth of a second in reality.
f you watch closely you can see new codes being tried about 15 times per second. It looks like all letters and numbers are being used. There are 62 letters and numbers, so it takes about 4 seconds to run through all 62 of them at 15 per second. This means that on average WOPR could have stumbled across the correct digit in each of the 10 positions in about 2 seconds. If it worked on one position at a time it should reach the correct code in about 20 seconds. Done, it's in, it launches, world war III commences and everyone gets time for one last hug before it's all over. In actual fact, computers even back in 1983 were capable of trying codes several thousand times per second, not 15, so that the whole process could have been completed in an eyeblink. This again underscores the reason why no computer security system would ever help an attacker by letting it know when it got one of the digits right.
adly i've seen this fallacy abused in dozens of big Hollywood flicks and it looks like there's no end in sight.
he other issue that annoys me is that when the actors are standing in front of the display with the camera pointing at them we can see the digits, in mirror image, being projected onto their faces. Before i discuss any technical issues with this, i'd like you to do an experiment for me. Open up your favorite word processor, type in a few numbers, set the font to something really huge, and change it to white text on a black background. Now have your friend, significant other, child, neighbor, or cat sit in front of the screen, up close. Do you see those numbers projected onto that person's face? Do you? No? Of course you don't. Sure, you see the light from the screen making their face brighter, but you don't see any actual digits. Have you ever seen this, ever with any computer or TV screen, anywhere at all, besides in a Hollywood movie? Of course you haven't.
n order for this to happen either the screen would have to be emitting coherent monodirectional light (like a laser) or there would have to be some focusing mechanism in front of the screen (like a lens). Now, let's say that you actually had such an arrangement. What would be the practical upshot? A focused beam of light comes together in one small point. It's only visible at that point. This is why a focused image looks sharp and clear where an unfocused one is blurry. It's because the light comes together in one point that you can make out an image. If it wasn't focused, it would be a blur and there would be no image. Since we see the image of the numbers on the faces in the movie, it must be focused. Now, imagine looking through a little peephole so that we only see a tiny portion of the person's face. If we are looking at a portion where the light from the number falls we'll see it. If we look slightly off to the side we don't see the light at all and couldn't even tell that it's there. The same is true with a laser light. You can't see the actual beam unless it's pointing into your eye (DO NOT DO THIS!!!). You can only see it where it hits something.
his works for the person who's face is having the numbers projected on it too. If the light from the projected number hits their eye, they'll see it. If not, they won't. So what would a person looking at such a screen see? Well, They would see the one tiny point of light from the one tiny point of the screen that is being projected into their eye. The entire rest of the screen would be black, because no light from that part of the screen is going into their eye at that moment. For that matter, anyone else looking at the screen would see different points than what you see. Sounds pretty useless, doens't it? And yet, Hollywood would still have you believe that this is the way that computer screens work.
hen will Hollywood ever learn?