Lava lamps, believe it or not, have various uses: they look cool, work great in low light, can keep me occupied for several hours, and can act as a random number generator for data encryption.
What the hell are you talking about?
In the San Francisco office lobby of renowned cloud network and online security company, CloudFlare, is a wall; but not just any wall–this wall holds 100 lava lamps that have a (not so) secret mission. It may seem like a weird 60s design fetish, but the lava lamp wall is actually used as one of CloudFlare’s many industry-grade random number generators for data encryption.
Photo: Dani Grant
The “Wall of Entropy”, as it’s aptly named, is the epitome of randomness. Now, randomness is crucial to data encryption so as to create patterns that an attacker won’t be able to replicate, but randomness is also incredibly difficult for computers to generate–which is not necessarily a bad thing.
“Computers from the beginning have been designed to very reliable, very predictable,” says CloudFlare’s CEO Matthew Prince.
SO, in order for computers to effectively utilise randomness, they need an external source. In this case, lava lamps.
OK, BUT HOW???
A camera takes a photo of the wall every millisecond of every day of the year and any of CloudFlare’s systems turns the pixels into random numbers. The degree of unpredictability is seemingly infinite, as the images change not only by the movement of the lava lamps but by people walking by and the shifting daylight. “Any tiny change in that photograph creates a completely random new set of inputs,” Prince says.
According to CloudFlare CTO, John Graham-Cumming, the lava lamp wall generates 16,384 bits of entropy per use.
The clever installations are a good way to engage customers and give an insight into what goes on behind closed doors. Prince says, “Nobody notices us when everything’s working correctly.” “The lava lamp wall [is a way] of us showing and demonstrating what it is that we’re doing behind the scenes.”