Cloudflare uses wave generators to generate truly random numbers

Cloudflare has introduced new sources of random numbers to encrypt its network traffic — the company announced in a blog post that it has created a “wall of entropy” made up of 50 wave generators at its new European headquarters in Lisbon. The completely unpredictable wave pattern is recorded by a camera and digitized. The truly random nature of the resulting data serves to protect the tens of millions of HTTPS requests that Cloudflare processes every second.

The company has developed its own, non-stop wave machine. A transparent parallelepiped 45 cm long is filled with half a liter of a unique liquid Hughes Wave Fluid Formula (consisting of two immiscible liquids) of different colors to create realistic “ocean waves.” The container with the liquid swings from side to side 14 times per minute or 20 thousand times per day. The wall was installed in March 2025, but the company says that the development took 15 months, and the idea itself appeared back in 2023. Most of the time was spent on improving the reliability of the mechanical components.

Image Source: Cloudflare

A Cloudflare spokesperson said the company was unable to acquire enough wave generators of the required size on eBay and other sources. As a result, it partnered with US-based Hughes Wave Motion Machines to build its own equipment.

Image Source: Cloudflare

Cloudflare is already known for using a wall of 100 lava lamps at its San Francisco headquarters to generate truly random numbers. The wall is also continuously filmed by a camera, digitizing the movement of liquid flows in the lamps. In London, an array of double pendulums is used, the shadows of which under different lighting conditions are also recorded by the camera. In the Texas office, the company uses a collection of suspended translucent elements (mobiles) that cast shadows on the walls – air flows, lighting and other factors create the required chaos. And in Singapore, the company even used a particle counter, “monitoring” the natural decay of uranium.