[bitcoin-dev] Trustless hash-price insurance contracts

JW Weatherman jw at mathbot.com
Sun Oct 20 14:10:55 UTC 2019


I think the assumption is not that all miners are unprofitable, but that a single miner could make an investment that becomes unprofitable if the hash rate increases more than he expected.

Depending on the cost of the offered insurance it would be prudent for a miner to decrease his potential loss by buying insurance for this possibility.

And the existence of attractive insurance contracts would lower the barrier to entry for new competitors in mining and this would increase bitcoins security.

-JW




‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Sunday, October 20, 2019 1:03 AM, Eric Voskuil via bitcoin-dev <bitcoin-dev at lists.linuxfoundation.org> wrote:

> Hi Lucas,
>
> I would question the assumption inherent in the problem statement. Setting aside variance discount, proximity premium, and questions of relative efficiency, as these are presumably already considered by the miner upon the purchase of new equipment, it’s not clear why a loss is assumed in the case of subsequently increasing hash rate.
>
> The assumption of increasing hash rate implies an expectation of increasing return on investment. There are certainly speculative errors, but a loss on new equipment implies all miners are operating at a loss, which is not a sustainable situation.
>
> If any miner is profitable it is the miner with the new equipment, and if he is not, hash rate will drop until he is. This drop is most likely to be precipitated by older equipment going offline.
>
> Best,
> Eric
>
> > On Oct 20, 2019, at 00:31, Lucas H via bitcoin-dev bitcoin-dev at lists.linuxfoundation.org wrote:
> > Hi,
> > This is my first post to this list -- even though I did some tiny contributions to bitcoin core I feel quite a beginner -- so if my idea is stupid, already known, or too off-topic, just let me know.
> > TL;DR: a trustless contract that guarantees minimum profitability of a mining operation -- in case Bitcoin/hash price goes too low. It can be trustless bc we can use the assumption that the price of hashing is low to unlock funds.
> > The problem:
> > A miner invests in new mining equipment, but if the hash-rate goes up too much (the price he is paid for a hash goes down by too much) he will have a loss.
> > Solution: trustless hash-price insurance contract (or can we call it an option to sell hashes at a given price?)
> > An insurer who believes that it's unlikely the price of a hash will go down a lot negotiates a contract with the miner implemented as a Bitcoin transaction:
> > Inputs: a deposit from the insurer and a premium payment by the miner
> > Output1: simply the premium payment to the insurer
> > Output2 -- that's the actual insurance
> > There are three OR'ed conditions for paying it:
> > A. After expiry date (in blocks) insurer can spend
> > B. Both miner and insurer can spend at any time by mutual agreement
> > C. Before expiry, miner can spend by providing a pre-image that produces a hash within certain difficulty constraints
> > The thing that makes it a hash-price insurance (or option, pardon my lack of precise financial jargon), is that if hashing becomes cheap enough, it becomes profitable to spend resources finding a suitable pre-image, rather than mining Bitcoin.
> > Of course, both parties can reach an agreement that doesn't require actually spending these resources -- so the miner can still mine Bitcoin and compensate for the lower-than-expected reward with part of the insurance deposit.
> > If the price doesn't go down enough, the miner just mines Bitcoin and the insurer gets his deposit back.
> > It's basically an instrument for guaranteeing a minimum profitability of the mining operation.
> > Implementation issues: unfortunately we can't do arithmetic comparison with long integers >32bit in the script, so implementation of the difficulty requirement needs to be hacky. I think we can use the hashes of one or more pre-images with a given short length, and the miner has to provide the exact pre-images. The pre-images are chosen by the insurer, and we would need a "honesty" deposit or other mechanism to punish the insurer if he chooses a hash that doesn't correspond to any short-length pre-image. I'm not sure about this implementation though, maybe we actually need new opcodes.
> > What do you guys think?
> > Thanks for reading it all! Hope it was worth your time!
> >
> > bitcoin-dev mailing list
> > bitcoin-dev at lists.linuxfoundation.org
> > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
> bitcoin-dev mailing list
> bitcoin-dev at lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev




More information about the bitcoin-dev mailing list