Post
Topic
Board Altcoin Discussion
Re: Qubic - Quorum-Based Coin
by
HanSolo
on 13/05/2013, 12:20:04 UTC
I can see that helping narrow the windows for problems, but it doesn't really answer what wins in disputes and how things resolve under network stress and malicious attacks.

Say the providers with transaction B are cut off for a few minutes around and after midnight, so they join the synchronization a little late. But they still have a 'valid' earlier timestamp. Did A get an advantage, becoming more likely to 'win', with its small head start?

With thousands nodes it doesn't matter if some of them have incorrect data. If u care about double-spending transactions, both transactions will be cancelled (http://qubic.boards.net/thread/14/double-spending).

I predict that will be problematic, for at least two reasons:

(1) In a large distributed system with many transient failure modes, there can be non-malicious errors that inadvertently create double-spends. Destroying the associated value is quite a harsh penalty.

(2) When arbitrarily many followup transactions depend on a double-spent value, and then some time later the double-spend becomes evident (requiring cancellation): (a) unwinding all followup transactions is hard and disruptive; (b) future compromise of private keys would seem able to retroactively cancel true, honest transactions the holder thought had already completed before the compromise.

Interesting, thank you, but I don't see an explanation how these peer-to-peer challenges result in a consensus determination of how many new qubics each provider receives. Is that in another thread/page?

Each provider decides how much QBC the other providers should get (https://bitcointalk.org/index.php?topic=112676.msg1219095#msg1219095).

Very interesting. Is this based on any other consensus-finding system with any history or study behind it? Preference-aggregation/voting systems are hard.

Does this assume every provider generally knows about (and can judge the minting offers/actions of) every other?

My hunch is that the large uncertainty of supply, and potential for disagreements to leave providers confused or seeking network partitions, could prevent the necessary critical mass of stakeholders and community norms from emerging.