A Wall of Waves Joins Cloudflare’s Entropy Network
Cloudflare’s Lisbon office, the company’s European headquarters, now houses a new source of cryptographic randomness: a wall of 50 wave machines in constant motion. The installation, which debuted on March 10, 2025, joins the lava lamps in San Francisco, suspended rainbows in Austin, and double chaotic pendulums in London as part of the company’s LavaRand system for securing Internet traffic.
The choice of waves is a nod to Portugal’s deep maritime heritage. The country has 980 km of coastline, maritime areas make up 90% of its territory, and its history of sea exploration dates back over 600 years. The town of Nazaré has been globally famous since 2011 for its giant waves, which hold Guinness World Records for the largest waves ever surfed. The office’s location, overlooking the Tagus River and the 25th of April Bridge, reinforces the theme.
From Desk Toy to Custom Build
The idea originated in 2023, when Cloudflare’s CEO, Matthew Prince, asked what could serve as a randomness source similar to the San Francisco lava lamp wall but representative of the Portuguese team. Wave motion machine desk toys, popular among some team members, provided the initial inspiration—fitting both the maritime theme and the scenic views.
Procurement proved challenging. Wave machines are no longer manufactured in the required size, and off-the-shelf models aren’t designed to run 24/7—a critical requirement. The company’s Places team found a U.S.-based artisan, Hughes Wave Motion Machines, a one-person business run by a former Lockheed Martin Space Systems engineer. Working together, they developed a custom rectangular machine (18 inches/45 cm long) that runs nonstop, requiring hundreds of hours of testing and many iterations. The final design features rotating wheels, continuous motors, and a proprietary fluid formula creating realistic ocean-like waves in green, blue, and Cloudflare’s signature orange.
“The machine’s design is a balancing act of matching components and their placement to how the fluid responds in a given configuration. There is a complex yet delicate relationship between viscosity, specific gravity, the size and design of the vessel, and the placement of each mechanical interface. Everything must be precisely aligned, centered around the fluid like a mathematical function. I like to say it’s akin to ’balancing a checkerboard on a beach ball in the wind.’”
Key specs of the entropy wall:
- 50 wave machines, each with a motion wheel, motor, and acrylic container filled with two immiscible liquids
- 3 liquid colors: blue, green, and orange
- 15 months from concept to completion
- 14 flips (side-to-side balancing movements) per minute—over 20,000 per day
- Over 15 waves per minute
- ~0.5 liters of liquid per machine
How LavaRand Works
Cloudflare’s servers handle 71 million HTTP requests per second on average, with peaks of 100 million—most secured via TLS, which relies on secure randomness. A Cryptographically Secure Pseudorandom Number Generator (CSPRNG) requires high-quality entropy seeds to ensure unpredictability. Since chaotic real-world movement is truly random, Cloudflare designed LavaRand to harness it.
Launched in 2017 and inspired by Silicon Graphics’ 1997 concept, LavaRand originally collected entropy from the San Francisco lava lamp wall. The system has since expanded to incorporate other sources of office chaos, including the Lisbon waves, while maintaining the same core method:
A camera captures images of the dynamic displays; shadows, lighting changes, and sensor noise all contribute entropy. Each image is processed into a compact hash, converted into random bytes, and combined with the previous seed and local system entropy. A Key Derivation Function (KDF) then generates a new seed for a CSPRNG, capable of producing virtually unlimited random bytes. The Lisbon waves now feed into this pool.
Cloudflare’s LavaRand API makes this randomness accessible internally, strengthening cryptographic security across global infrastructure. When you use Math.random() in Cloudflare Workers, part of that randomness comes from LavaRand; the drand API also taps into it. Cloudflare offers this API for anyone to generate random numbers or seed their own systems.
Design Language of Chaos
Entropy also informed the broader design of the Lisbon office, which was a single project with the wave wall. The entrance features the wave installation next to a Cloudflare Radar Display showing the constant movement of planet Earth. Wave motifs continue throughout the space—in ceiling lights, architectural contours, and the floor plan—reflecting the fluid movement of water, though the building’s Internet traffic, unlike ocean tides, ebbs and flows with the sun’s motion. Meeting rooms are named after famous Portuguese beaches, including Nazaré.
The construction project partnered with local Portuguese vendors, notably with women in all lead roles—a rarity for the industry. The local teams worked with pride on the project, describing it as distinct from their previous work.
Cloudflare is seeking public input on naming the new wall. The candidate names are: The Surf Board, Chaos Reef, Waves of Entropy, Wall of Waves, Whirling Wave Wall, Chaotic Wave Wall, and Waves of Chaos. Voting is open via an online form. The company is also hiring for its Lisbon office and other global locations.
