So it turns out that 10% of all the traffic on the internet is encrypted with the help of Lava Lamps. That’s awesome, right? I love Lava Lamps and used to own a half dozen of them, but who knew they could be one of the keys to encryption? Fast Company Design did a story about how Cloudflare uses Lava Lamps as a super random number generator.
Here’s how it works: Cloudflare offers content delivery network services, protections against denial of service attacks, and and anti-bot protections. Many of the Bitcoin faucets in my faucet guide, for instance, use Cloudflare to test your browser to see if you’re a real human. They do other stuff, too, including distributed domain name server services, and encryption services.
All in all, Cloudflare claims that 10% of the world’s internet traffic go through their servers. To encrypt that traffic, the company employs a wall of 100 Lava Lamps in its San Francisco office. A camera take a picture of that wall every millisecond. Each picture is different as the Lava Lamps do their thing. Cloudflare’s servers use the pixels of those images when it needs to generate a random number.
Fluid dynamics are hard, and no one has figured out how to predict the movements inside a Lava Lamp, let alone a hundred of them. That means the random numbers being used in Cloudflare’s encryption are truly random (effectively, at least).
That is as clever as it is fun. Cloudflare also uses a double pendulum in the same way at its London office. In Singapore, Cloudflare measures decaying isotopes off a pellet of uranium. You can read more about it at Fast Company Deisgn, including picture of the wall taken by Dani Grant, an amazing photographer.