5 ms·

Probably because such a system is not provably fair – you can’t prove your system is truly random.

• jedberg 5y ago
  You would use an external source of randomness, which you can definitely prove is sufficiently random.
  • teddyh 4y ago
    You could do something like this: • Pre-publish, for each time batch, a public key. You could publish lists of these well in advance. • Let everyone submit, alongside each order, a number arbitrarily selected by them. It does not matter how they select the number, but it would be simpler if everyone chose distinct numbers. • When order processing is done, do it by the order of closeness of the submitted number to the private key. Publish the private key after order submission is closed. • Everybody can now verify that the order of processing is indeed by the order of the previously secret private key, and everybody can verify that the private key corresponds to the previously published private key.
    • jedberg 4y ago
      That seems unnecessary. Today the traders have to trust the exchange to process fairly and in order -- there is no verifiability. The verifiability would be nice, but unnecessary.
    • can16358p 4y ago
      Something very similar is done on smart contracts to introduce randomness (at least to the practical extent) on blockchain. Good thought experiment nevertheless to provably inject randomness into a system with untrusting parties.
      • namibj 4y ago
        Oh, there are trust-less coin flip protocols. Edit: see https://en.wikipedia.org/wiki/Commitment_scheme#Coin_flipping https://en.wikipedia.org/wiki/Commitment_scheme#Coin_flippin...
    • Natfan 4y ago
      Alternatively, just do what Cloudflare does (did?), and have some cameras pointed at lava lamps[0]. [0]: https://www.youtube.com/watch?v=1cUUfMeOijg https://www.youtube.com/watch?v=1cUUfMeOijg