Classifying a Shape
This is a great essay:
Spheres are special shapes for nuclear weapons designers. Most nuclear weapons have, somewhere in them, that spheres-within-spheres arrangement of the implosion nuclear weapon design. You don’t have to use spheres -- cylinders can be made to work, and there are lots of rumblings and rumors about non-spherical implosion designs around these here Internets -- but spheres are pretty common.
Imagine the scenario: you’re a security officer working at Los Alamos. You know that spheres are weapon parts. You walk into a technical area, and you see spheres all around! Is that an ashtray, or it is a model of a plutonium pit? Anxiety mounts -- does the ashtray go into a safe at the end of the day, or does it stay out on the desk? (Has someone been tapping their cigarettes out into the pit model?)
All of this anxiety can be gone -- gone! -- by simply banning all non-nuclear spheres! That way you can effectively treat all spheres as sensitive shapes.
What I love about this little policy proposal is that it illuminates something deep about how secrecy works. Once you decide that something is so dangerous that the entire world hinges on keeping it under control, this sense of fear and dread starts to creep outwards. The worry about what must be controlled becomes insatiable and pretty soon the mundane is included with the existential.
The essay continues with a story of a scientist who received a security violation for leaving an orange on his desk.
Two points here. One, this is a classic problem with any detection system. When it's hard to build a system that detects the thing you're looking for, you change the problem to detect something easier -- and hope the overlap is enough to make the system work. Think about airport security. It's too hard to detect actual terrorists with terrorist weapons, so instead they detect pointy objects. Internet filtering systems work the same way, too. (Remember when URL filters blocked the word "sex," and the Middlesex Public Library found that it couldn't get to its municipal webpages?)
Two, the Los Alamos system only works because false negatives are much, much worse than false positives. It really is worth classifying an abstract shape and annoying an officeful of scientists and others to protect the nuclear secrets. Airport security fails because the false-positive/false-negative cost ratio is different.
Posted on January 3, 2013 at 6:03 AM • 34 Comments