4 ms·

I really don't understand how this is useful. If you have several sources of randomness, even if they are weak, can you not run them through a cryptographically

I really don't understand how this is useful. If you have several sources of randomness, even if they are weak, can you not run them through a cryptographically strong hash function and get a more random output? The voting system sounds even weirder. How does taking groups of threes solve malicious voters? What even are malicious voters?

DanBC 10y ago
> The voting system sounds even weirder. How does taking groups of threes solve malicious voters? What even are malicious voters? This is normally talked about in terms of biased coin tosses. You know Von Neumann's de-skew technique? http://pit-claudel.fr/clement/blog/generating-uniformly-random-data-from-skewed-input-biased-coins-loaded-dice-skew-correction-and-the-von-neumann-extractor/ http://pit-claudel.fr/clement/blog/generating-uniformly-rand... > If independence of successive tosses is assumed, we can reconstruct a 50-50 chance out of even a badly biased coin by tossing twice. If we get heads-heads or tails-tails, we reject the tosses and try again. If we get heads-tails (or tails-heads), we accept the result as heads (or tails). I'm not sure why the submitted article is any different from this technique.
- Houshalter 10y ago
  Ok that makes sense for random numbers, but I'm not sure how it would apply to a real world election.
- sukilot 10y ago
  BTW, there is no such thing as a biased coin, only a biased flipping mechanism. You can't inherently bias a flipped coin like you can bias a die. You can create a biased 2-state generator , but not with a flipped coin.
  - DanBC 10y ago
    Yes, but these are mathematical coins not real world objects. (I upvoted your post. I don't think it deserved the downvote(s)).
billmalarky 10y ago
I thought hash functions only removed entropy? I guess it depends on if the hash method has less output than input?
Retra 10y ago
The only way that would make sense is if your hash function is random. That's typically not how hash functions are built, since it would largely render them useless. A cryptographically strong hash function only tries to guarantee that there is no predictable order to the hashes, not that the hashes are random.
- Houshalter 10y ago
  Well of course they aren't random, it's a deterministic function. But the algorithm proposed is also a deterministic function. Both claim to produce scrambled outputs from semi random inputs. But it's not clear why this method is superior.
  - Retra 10y ago
    I think the idea here is that you can take two weak sources of randomness and combine them into a stronger, single source of randomness in a homogenous way that doesn't reveal the original weaknesses. Thus it's not adding randomness from nowhere, but composing it in a useful way. I don't actually know, but that's the only interpretation I could come up with that makes sense to me.

DanBC 10y ago

> The voting system sounds even weirder. How does taking groups of threes solve malicious voters? What even are malicious voters? This is normally talked about in terms of biased coin tosses. You know Von Neumann's de-skew technique? http://pit-claudel.fr/clement/blog/generating-uniformly-random-data-from-skewed-input-biased-coins-loaded-dice-skew-correction-and-the-von-neumann-extractor/ http://pit-claudel.fr/clement/blog/generating-uniformly-rand... > If independence of successive tosses is assumed, we can reconstruct a 50-50 chance out of even a badly biased coin by tossing twice. If we get heads-heads or tails-tails, we reject the tosses and try again. If we get heads-tails (or tails-heads), we accept the result as heads (or tails). I'm not sure why the submitted article is any different from this technique.

Houshalter 10y ago
Ok that makes sense for random numbers, but I'm not sure how it would apply to a real world election.
sukilot 10y ago
BTW, there is no such thing as a biased coin, only a biased flipping mechanism. You can't inherently bias a flipped coin like you can bias a die. You can create a biased 2-state generator , but not with a flipped coin.
- DanBC 10y ago
  Yes, but these are mathematical coins not real world objects. (I upvoted your post. I don't think it deserved the downvote(s)).

billmalarky 10y ago

I thought hash functions only removed entropy? I guess it depends on if the hash method has less output than input?

Retra 10y ago

The only way that would make sense is if your hash function is random. That's typically not how hash functions are built, since it would largely render them useless. A cryptographically strong hash function only tries to guarantee that there is no predictable order to the hashes, not that the hashes are random.

Houshalter 10y ago
Well of course they aren't random, it's a deterministic function. But the algorithm proposed is also a deterministic function. Both claim to produce scrambled outputs from semi random inputs. But it's not clear why this method is superior.
- Retra 10y ago
  I think the idea here is that you can take two weak sources of randomness and combine them into a stronger, single source of randomness in a homogenous way that doesn't reveal the original weaknesses. Thus it's not adding randomness from nowhere, but composing it in a useful way. I don't actually know, but that's the only interpretation I could come up with that makes sense to me.