Edge compute and network firm Cloudflare has deployed a series of wave machines at its office in Portugal as a source of random number generation for its network encryption.

In a blog post this week, the company said it deployed a “wall of entropy” made of 50 wave machines in constant motion at its new European HQ in Lisbon.

The random and unpredictable waves are recorded by a camera, digitized and given a numerical value. This random number then informs the encryption keys for the 71 million HTTP requests per second the company averages every day.

The company developed a custom rectangular wave machine (18 inches/45 cm long) that runs non-stop. The machines are equipped with rotating wheels, continuous motors, and half a liter of unique fluid formula, to create realistic ocean-like waves in green, blue, and orange.

Wave machines were chosen to tie in with Portugal’s seafaring history. Each machine ‘flips’ some 14 times per minute (20,000 times per day).

The development of the wall reportedly required “hundreds of hours of testing and many iterations.”

The wall was deployed in March 2025, but the blog suggests that it had been in development for 15 months, with the original idea forming back in 2023. One image in the blog from March 2024 showed the team testing wave machine placement, shelves, lighting, and mirrors to enhance movement and reflection.

On X (formerly Twitter) Matthew Prince, co-founder and CEO of Cloudflare described how the company struggled to source enough of the right sized wave machines from eBay and other sources that were in working order. The company ended up partnering with US firm Hughes Wave Motion Machines to create bespoke devices.

Chasing randomness

Cloudflare famously uses a wall of 100 lava lamps at its San Francisco headquarters in California as a source of randomness for encryption keys. A camera records the unique and unpredictable blobs created by each lamp, which are converted into digital pixels and given numerical values via the company’s LavaRand software, creating unique encryption keys for the company’s servers.

Previously, Cloudflare said its servers relied on local sources of entropy (such as the precise timing of packet arrivals or keyboard events) as random seeds to begin the random number generation and encryption process.

The company has been using the lava lamps since 2017, and has rolled out other physical random number generators at other locations around the world.

In London, UK, Cloudflare has a wall of double pendulums, with the shadows of the swinging arms in different light conditions creating the desired randomized and unpredictable values.

At its office in Austin, Texas, the company has a collection of translucent rainbow mobiles hanging from the ceiling next to the entrance. The mobiles cast shadows on the walls – which change depending on the lighting conditions, air conditioning, and breeze from doors opening and closing – and create the desired chaos that is recorded and digitized.

The company is also known to use radioactive decay as a source of randomness at its Singapore office. Fast Company reported back in 2017 that the company had a pellet of uranium encased in a glass bell jar on display. The release of isotopes over time is recorded using a Geiger counter, and again converted into a numerical value to inform its encryption.