When you encrypt a piece of data—like, say, your credit card number—your computer hides this information from prying eyes based on a key known only to the sender and the receiver. The longer and more random the key, the tougher the encryption is to crack if a third party intercepts your message and tries to figure out what you sent.
Encryption can range from simple algorithms—a one-bit key like X = (X + 1), which just shifts the value of your data so the word “CAT” appears as “BZS”—to incredibly complex algorithms. And that's where lava lamps come into play.
The San Francisco-based Internet security firm Cloudflare doesn't just use these oozy lights to evoke a '60s feeling in its lobby. The patterns created by the hot wax helps the company create encryption keys that meet the gold standard for random number generation: they weren't made by a human, nor were they created by the hardware used to send or receive encrypted data.
Plus, they look great.
Lava lamps are just as cool as radioactive decay
Here's a fun weekend project. Get some radioactive material, pull your your trusty Geiger counter, and measure the radioactive decay. Tracking the frequency of your counter's "clicks" can give you a sequence that's truly random—in other words, a great encryption key.
This process may make physicists and some IT nerds all giddy, but it's not that exciting. Over at Cloudflare, the company uses uses a sexy alternative that objectively yields the same randomized results – a wall of 100 lava lamps.
A hi-resolution digital camera captures 2-D images of the lamps, which can collectively generate infinite patterns. The digital image files become streams of random numbers that are then fed into their system as (huge) encryption keys.
The lava lamp's mortal enemy: your video card
Why this obsession with randomization? The answer lies in the growing power of off-the-shelf hacking equipment. Nowadays, a decent hacker’s system isn't a supercomputer housed in a university basement. It's a home desktop that can run games in 4K or brute-force complicated encryption keys without breaking much of a sweat—depending on the size of the key (or password). Thankfully, your average gaming PC (or cluster of gaming PCs) is no match for a wall of lava lamps—for now.