Lavarand

A wall of lava lamps at the offices of Cloudflare

Lavarand, also known as the Wall of Entropy, was a hardware random number generator designed by Silicon Graphics that worked by taking pictures of the patterns made by the floating material in lava lamps, extracting random data from the pictures, and using the result to seed a pseudorandom number generator.[1]

  1. ^ "Totally Random". Wired Magazine. Vol. 11, no. 8. August 2003.