cross-posted from: https://feddit.org/post/36134515

https://www.cloudflare.com/learning/ssl/lava-lamp-encryption/

since the motion of fluids is notoriously hard to compute, this makes for a good source of randomness.

I think they just wanted a wall of lavalamps.

IMO this is more PR than anything. The lava lamps are far away from the camera that the variance in pixel data from the lava lamps is low. Think about the percentage of pixels changing compared to the total camera space and the range of pixel data.

I've heard about pointing a camera at a black surface, then massively upping the gain which causes the camera to oversaturate the noise in the sensor measuring process to get random seed data.

yeah but even if only 1 pixel changes, if you take the hash value of the image data, you'll still get some entirely different numbers.

Now I want a wall of lava lamps.

I feel that I read about something very similar nearly 25 years ago

Because that’s about when they started doing it. It’s a TIL, not a news article.

Now everyone wants a wall of lava lamps

Fun fact: theres an app for the flipper zero that uses the ir receiver and a lighter to generate random numbers.

No the lava lamps were a real thing. But they aren’t used any more. They said they moved to post quantum crypto now, so they can’t rely on that tech any more.

But the lava lamp randomness was a real thing while it lasted.

Where can I get me one of those? Flipper zero, not lighter.

Invented by SGI in 1996, so fully three decades ago now.

https://en.wikipedia.org/wiki/Lavarand

Also, even the open-source successor is so old that they released it on Sourceforge, of all places.

https://flipper.net/

Ok, but it's going to get really hot.

The lesser known game "the wall is lava lamps"

lamps*

As pointed out by others as well, this is not used anymore. It's interesting but an artefact from the past.

Relevant Tom Scott video

99 lamps of lava on the wall, 99 lamps of lava ...