alt Hacker NewsThis is why CloudFlare has done what they did with the lava lamp wall. Not that the wall is such a great source of entropy on its own - I'm sure it's not their only source, but you can never have too many sources of entropy - but it makes it visible in a way that can grab those who don't fully understand the concepts of RNGs and how entropy plays into that.
The more sources of entropy, the more closely you approach "perfect" randomization. And a large chunk of those entropy sources need to be non-deterministic. Even on the small level, local applications running on local systems, like games, can use things like the mouse coordinates, the timings between button presses, the exact frame count since game start before the player presses Start to greatly enhance randomness while still using PRNGs under the hood
Yes, for the latter, that's technically deterministic (and the older the game considered, the more deterministic it is, see TAS runs of old games obliterating the "RNG"). But when you have fifty different parameters feeding into the initial seed, that's fifty things an attack would have to perfectly predict or replay (and there are other ways to avoid replay attacks that can be layered on top)
If CloudFlare had less than 100 different sources of entropy, I'd be disappointed. And that's assuming their algorithm for blending those entropy sources into a single seed value is good
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If I understand it the Lava lamps are 90% PR/fun. They have a lot of other sources for entropy that scales better.
Old games are RTA viable to RNG manip: https://m.youtube.com/watch?v=Bgh30BiWG58
The lava lamps are just for show.
You can get entropy just by plugging an oscilloscope into a pile of dirt and cranking the gain up.
> you can never have too many sources of entropy
This is so true. And the beauty is that with algorithms, we don't even need to know much about the entropy to be able to extract it.
There is the Von Neumann method of generating an unbiased coin from a biased coin. Of throwing it twice, and checking if you got HT or TH. And completely discarding all HH or TT results. It doesn't matter if the coin you are using is 20% or 80%, the result will be a true 50/50.
There are more modern algorithms that can be even better (in that they need less coin tosses if you have a very unbalanced coin).
And then there is modern cryptographic hashing. Feed it all the bits you can. Collisions end up only happening in the real world if every single one of those bits is identical. So if you have actual entropy being fed, that cannot be controlled, predicted, or replicated, modern cryptography tells you that the end result is unique.