3 ms·

But are they more random than a wall of lava lamps? https://en.wikipedia.org/wiki/Lavarand https://en.wikipedia.org/wiki/Lavarand In all seriousness, the move

But are they more random than a wall of lava lamps? https://en.wikipedia.org/wiki/Lavarand https://en.wikipedia.org/wiki/Lavarand In all seriousness, the movement of large objects would seem inherently more random than the movements of individual particles. The actual number and real points of failure come not from the objects but from the devices that measure their position.

jjn2009 5y ago
> the movement of large objects would seem inherently more random than the movements of individual particles sounds contrary to law of large numbers
323 5y ago
Being small means you can integrate it in the CPU die. This is very important for SecureBoot/DRM kind of things, because it means you can't easily manipulate the secure processor entropy. I know HN doesn't like SecureBoot or DRM, but this kind of stuff guards against maid attacks. For example with a lava-lamp someone could replace your webcam with a hacked one that manipulates the picture in a subtle way that removes entropy. But you can't replace a SecureBoot CPU, it will be noticed if the TPM lives inside the CPU.
- nagisa 5y ago
  A ring oscillator circuit is small and fast too. I'd be curious to hear how this new idea compares to the contemporary approach.
charcircuit 5y ago
It was my understating that the randomness primarily comes from sensor noise and not from the lava lamps themselves.
- Osiris 5y ago
  https://blog.cloudflare.com/lavarand-in-production-the-nitty-gritty-technical-details/ https://blog.cloudflare.com/lavarand-in-production-the-nitty... Sensor noise absolutely part of it but if that were the only source then pointing the camera at a fixed image would be fine. In this case, the combination of the randomness of the lamps plus that of the sensors noise makes it more difficult for an attacker (just taking a picture of the same lamps at the same time won't be enough).
  - ncmncm 5y ago
    Pointing the camera at a fixed image would, in fact, be fine. The lava lamp is just for publicity. Any old camera attached to any old gadget provides more truly random bits than you will ever need, no matter where it is pointed, or isn't. A microphone, likewise. A radio receiver, likewise. People rolling dice to get random numbers is the height of silliness. Using a specially built gadget is about equally silly: you never know if you built it right. AMD shipped microprocessors with a "true random number generator" device, and instruction to access it, that gave wholly non-random numbers. They had to distribute a microcode patch for that, demonstrating that microcode is able to deny you those supposedly truly-random bits any time the spooks like.

jjn2009 5y ago

> the movement of large objects would seem inherently more random than the movements of individual particles sounds contrary to law of large numbers

323 5y ago

Being small means you can integrate it in the CPU die. This is very important for SecureBoot/DRM kind of things, because it means you can't easily manipulate the secure processor entropy. I know HN doesn't like SecureBoot or DRM, but this kind of stuff guards against maid attacks. For example with a lava-lamp someone could replace your webcam with a hacked one that manipulates the picture in a subtle way that removes entropy. But you can't replace a SecureBoot CPU, it will be noticed if the TPM lives inside the CPU.

nagisa 5y ago
A ring oscillator circuit is small and fast too. I'd be curious to hear how this new idea compares to the contemporary approach.

charcircuit 5y ago

It was my understating that the randomness primarily comes from sensor noise and not from the lava lamps themselves.

Osiris 5y ago
https://blog.cloudflare.com/lavarand-in-production-the-nitty-gritty-technical-details/ https://blog.cloudflare.com/lavarand-in-production-the-nitty... Sensor noise absolutely part of it but if that were the only source then pointing the camera at a fixed image would be fine. In this case, the combination of the randomness of the lamps plus that of the sensors noise makes it more difficult for an attacker (just taking a picture of the same lamps at the same time won't be enough).
- ncmncm 5y ago
  Pointing the camera at a fixed image would, in fact, be fine. The lava lamp is just for publicity. Any old camera attached to any old gadget provides more truly random bits than you will ever need, no matter where it is pointed, or isn't. A microphone, likewise. A radio receiver, likewise. People rolling dice to get random numbers is the height of silliness. Using a specially built gadget is about equally silly: you never know if you built it right. AMD shipped microprocessors with a "true random number generator" device, and instruction to access it, that gave wholly non-random numbers. They had to distribute a microcode patch for that, demonstrating that microcode is able to deny you those supposedly truly-random bits any time the spooks like.