Why the security of millions of websites depends on 100 lava lamps

The Cloudflare lava lamp wall is proudly displayed – after all, it is very important to the company. (Image: Cloudflare)

Cloudflare is one of the largest providers of Internet security services and content delivery networks (CDNs). The company plays a crucial role in securing millions of websites from cyber threats and is a big part of our ability to surf the Internet quickly.

However, behind the scenes of such an important tech company lies an unexpected tool: 100 lava lamps.

You can find out here what retro decoration has to do with internet security.

Lava lamps are better at randomness than computers

Random values ​​are extremely important for encrypting data. Any key a computer uses to encrypt data must be truly random – otherwise it will be possible for attackers to decrypt it.

The problem with this: Computers work logically and are very bad at generating true random values. The real world offers a significantly better source of random values ​​- as Cloudflare, among others, has discovered.

The company’s solution: 100 lava lamps located in the lobby of Cloudflare headquarters. The “lava” in the lamps never takes the same shape, and 100 of them is an excellent source of randomness.

No single photo of the lava lamp wall is the same: a perfect source of random values. (Image: Cloudflare)

A camera in the lobby takes photos of the lava lamp wall at regular intervals, and no two pictures are the same. And because digital images are just sequences of numbers and every pixel has a numerical value, the photos can be saved as completely randomly generated sequences of numbers.

These are then used to generate secure encryption codes. This is how a simple decorative object from the last decades becomes a high-tech tool.

By the way: Visitors and employees can simply stand in front of the lava lamps if, for example, they want to take pictures of them themselves – they then simply become part of a new security key.

If you want to find out more about Cloudflare’s lava lamps, we recommend the video from Tom Scott, who looked at the lamps on site:

Link to YouTube content

Why aren’t computers suitable for generating random values?

Computers work based on rules. These rules are always the same, so the result of a calculation is always the same. For example, the number 7 is always output when the number 4 is added to the number 3.

Computers are unable to replicate the unpredictability of reality. This means that computer-generated random numbers always have a pattern that can be analyzed and predicted. However, computers can simulate random values ​​using so-called PRNGs.

Pseudorandom number generators (PRNGs) are algorithms that simulate random numbers. They use a set of rules to generate a sequence of numbers from a seed. This sequence seems random, but in reality it is predictable.

PRNGs are used in many areas, including gaming, graphics, simulation, and cryptography. However, in applications where high security is required, hardware-based random number generators are typically used – like Cloudflare’s lava lamps.

Example: Minecraft worlds

The worlds in Minecraft appear to be randomly generated, but they actually aren’t.

The worlds in Minecraft are generated with a seed. The seed is the starting value for the PRNG. Changing the seed leads to a different world. However, the sequence of numbers generated is always the same for each seed.

This means that every Minecraft world generated with the same seed will be identical.

We hope you learned something new from this article or had fun reading it!

By the way, lava lamps are not the only source of random values ​​used by tech companies. For example, Cloudflare’s Singapore office photographs the radioactive decay of a uranium bead. Did you know that such lamps are used to generate security keys? Write it to us in the comments!