7 ms·

First atomic bet on Bitcoin Cash using new opcodes

76 points by ca98am79 8y ago

fastball 8y ago
Can I get a supporter of BTC/BCH explain to me why it makes sense to do this on those blockchains rather than on a blockchain with actual Turing completeness, such as Ethereum?
- 456hdsaq234g 8y ago
  because in bcash land they can convince the miners to include tx's with 1 satoshi fee, so they can bloat their chain with all kinds of junk like yours.org Good luck doing that in ethereum land.
  - akerro 8y ago
    They also hate volunteers who run BCH nodes, 32MB blocks will wear-out harddrives quickly.
    - gasull 8y ago
      Wrong. BCH will run in Raspberry Pis just fine thanks to UTXO commitments. No need for large hard drives. https://www.yours.org/content/first-utxo-commitment-on-testnet-db7bf45bf83d https://www.yours.org/content/first-utxo-commitment-on-testn...
      - grubles 8y ago
        Your "wrong" is wrong. You still need large storage devices if you want to trustlessly verify transaction history.
        gasull 8y ago
        Your "'wrong' is wrong" is wrong. Yo can verify transaction history with an SPV wallet. A full node won't help you against an eclipse attack. And also not against a sustained 51% attack since miners can mine empty blocks on the minority chain, halting it. A full node is good for increasing your privacy, disguising what addresses you're watching, but that's all.
- brighton36 8y ago
  Virtue compliance. Same reason you'd use ethereum.
- edf13 8y ago
  Because of usage & volume... More users of BTC/BCH than ETH.
  - fastball 8y ago
    Is that really true in the case of BCH vs. ETH? I find that hard to believe given the number of ICOs / developers working on the Ethereum blockchain.
    - edf13 8y ago
      Ok - probably right for BCH.. my rush on posting, so my bad. Not the best indicator but.. https://coinmarketcap.com/currencies/ethereum/ https://coinmarketcap.com/currencies/ethereum/ vs https://coinmarketcap.com/currencies/bitcoin-cash/ https://coinmarketcap.com/currencies/bitcoin-cash/ But for BTC I'd say yes.
    - gasull 8y ago
      BCH has less users than ETH. I think the interest is that transactions in BCH are very low, and there are talks about enabling some 0-fee transactions: https://coingeek.com/bitcoin-com-viabtc-join-miners-choice-initiative-bitcoin-cash-miners/ https://coingeek.com/bitcoin-com-viabtc-join-miners-choice-i... An important difference between BCH and ETH is that ETH has a lot of opcodes, but BCH is slowly enabling some of the opcodes that were created by Satoshi but later disabled.
  - grubles 8y ago
    There are absolutely not more users of Bcash than Ethereum.
- zilchers 8y ago
  There have been some other answers, but I’ll add first, people may just want to bet BCH - if it’s possible to do, even with a limited instruction set, why not figure it out? Second, turing completeness is not a panacea, and as we’ve seen now several times, the expressiveness of Eth’s VM actually opens it up to more bugs.
- xiphias 8y ago
  With BTC there's practically no person who can revert the trqnsaction. On the other hand if Vitalik loses a $1B bet on the Eth chain... Another reason is that with BTC you can verify the whole blockchain on an average computer, with ETH full verification is turned off by all implementations by default for a reason.
456hdsaq234g 8y ago
The OP_CODES were 'disabled' by core because they were considered poorly tested and a consensus logic risk. https://github.com/bitcoin/bitcoin/pull/2610 https://github.com/bitcoin/bitcoin/pull/2610 Of course, the highly skilled 'Bitcoin ABC' aka bcash developers obviously tested these well, with no risk to consensus logic or users funds...
- yrro 8y ago
  Can we please avoid having HN becoming yet another battleground for Core vs Cash sock puppets to dump their trollish posts?
  - akerro 8y ago
    Tell people to stop upvoting these threads, don't tell commenters to stop explaining issues and providing sources.
    - fastball 8y ago
      Eh, I think this belongs here. Heavy moderation is probably good to prevent the BTC/BCH flame wars you'll see on other forums, but the technical differences being introduced between the chains (such as OP_CODES here) are actually very interesting I think.
    - ddtaylor 8y ago
      I thought asking people to upvote or downvote content on HN was against the rules?
      - windows_tips 8y ago
        >Please don't impute astroturfing or shillage. That degrades discussion and is usually mistaken. If you're worried about it, email us and we'll look at the data. >Please don't complain that a submission is inappropriate. If a story is spam or off-topic, flag it. Don't feed egregious comments by replying; flag them instead. If you flag something, please don't also comment that you did. >Please don't comment about the voting on comments. It never does any good, and it makes boring reading.
lawlessone 8y ago
>an atomic bet guarantees that the winner will be paid no matter what. How is this possible? is there an Oracle all parties agree to trust? edit:i see how this can work for some sort of bet where the result is calculated on the blockchain itself but outside of that?
- zilchers 8y ago
  It relies on the parties to take an action (that they are both incentivized to take in order to see if they won). This is similar to atomic swaps - they setup a time boxed window when people must take an action. If one of the parties fails to act in time, they will, in fact, lose their coins.
nwah1 8y ago
Just so we're clear, we're talking about a virtual coin flip here, right? Anything else would require trust. Even if you tried to use an API that checked the scores of a sporting event.
- detaro 8y ago
  yes, it's just a coin flip.
  - lawlessone 8y ago
    Now i'm wondering, what is the ratio of odd to even outputs when calculating this? are they perfectly even or is one more likely for each flip?
- tylersmith 8y ago
  The example is a coin flip but it could be any random based game by using a different algorithm than "number mod 2". You're correct that it can't act on real world data.
  - nwah1 8y ago
    Could this be modified to support, say, a chess game?
    - tylersmith 8y ago
      Chess doesn't have any random element so it wouldn't need this kind of system. You could implement card games and board games that do have randomness like candyland. You could implement chess with only movement commitments and no atomic fair random number generation.
      - detaro 8y ago
        Some aspects of it would be interesting for non-random games too, e.g. the payout if one player stops submitting moves, verifying who won, ..
Immune 8y ago
This is similar to https://github.com/Jfaler/Bitcoin-Casino https://github.com/Jfaler/Bitcoin-Casino
josu 8y ago
The interesting thing about this is that all the logic happens onchain. This is why OP mentions that this is the first truly decentralized bet of this kind, because everything is happening on top of the Bcash decentralized protocol. TL;DR: A very simple smart contract running on the Bcash network.
DennisP 8y ago
I didn't realize this was possible on Bitcoin Cash. Here's a similar idea coded for Ethereum: https://www.blunderingcode.com/gamble-channels-fast-verifiable-off-chain-gambling/ https://www.blunderingcode.com/gamble-channels-fast-verifiab... This uses a chain of hashes so you can make a single commitment for lots of bets, and an off-chain payment channel.
grover_hartmann 8y ago
bcash is trash. https://www.youtube.com/watch?v=oCOjCEth6xI https://www.youtube.com/watch?v=oCOjCEth6xI

76 points by ca98am79 8y ago

Can I get a supporter of BTC/BCH explain to me why it makes sense to do this on those blockchains rather than on a blockchain with actual Turing completeness, such as Ethereum?

456hdsaq234g 8y ago
because in bcash land they can convince the miners to include tx's with 1 satoshi fee, so they can bloat their chain with all kinds of junk like yours.org Good luck doing that in ethereum land.
- akerro 8y ago
  They also hate volunteers who run BCH nodes, 32MB blocks will wear-out harddrives quickly.
  - gasull 8y ago
    Wrong. BCH will run in Raspberry Pis just fine thanks to UTXO commitments. No need for large hard drives. https://www.yours.org/content/first-utxo-commitment-on-testnet-db7bf45bf83d https://www.yours.org/content/first-utxo-commitment-on-testn...
    - grubles 8y ago
      Your "wrong" is wrong. You still need large storage devices if you want to trustlessly verify transaction history.
      - gasull 8y ago
        Your "'wrong' is wrong" is wrong. Yo can verify transaction history with an SPV wallet. A full node won't help you against an eclipse attack. And also not against a sustained 51% attack since miners can mine empty blocks on the minority chain, halting it. A full node is good for increasing your privacy, disguising what addresses you're watching, but that's all.
brighton36 8y ago
Virtue compliance. Same reason you'd use ethereum.
edf13 8y ago
Because of usage & volume... More users of BTC/BCH than ETH.
- fastball 8y ago
  Is that really true in the case of BCH vs. ETH? I find that hard to believe given the number of ICOs / developers working on the Ethereum blockchain.
  - edf13 8y ago
    Ok - probably right for BCH.. my rush on posting, so my bad. Not the best indicator but.. https://coinmarketcap.com/currencies/ethereum/ https://coinmarketcap.com/currencies/ethereum/ vs https://coinmarketcap.com/currencies/bitcoin-cash/ https://coinmarketcap.com/currencies/bitcoin-cash/ But for BTC I'd say yes.
  - gasull 8y ago
    BCH has less users than ETH. I think the interest is that transactions in BCH are very low, and there are talks about enabling some 0-fee transactions: https://coingeek.com/bitcoin-com-viabtc-join-miners-choice-initiative-bitcoin-cash-miners/ https://coingeek.com/bitcoin-com-viabtc-join-miners-choice-i... An important difference between BCH and ETH is that ETH has a lot of opcodes, but BCH is slowly enabling some of the opcodes that were created by Satoshi but later disabled.
- grubles 8y ago
  There are absolutely not more users of Bcash than Ethereum.
zilchers 8y ago
There have been some other answers, but I’ll add first, people may just want to bet BCH - if it’s possible to do, even with a limited instruction set, why not figure it out? Second, turing completeness is not a panacea, and as we’ve seen now several times, the expressiveness of Eth’s VM actually opens it up to more bugs.
xiphias 8y ago
With BTC there's practically no person who can revert the trqnsaction. On the other hand if Vitalik loses a $1B bet on the Eth chain... Another reason is that with BTC you can verify the whole blockchain on an average computer, with ETH full verification is turned off by all implementations by default for a reason.

456hdsaq234g 8y ago

The OP_CODES were 'disabled' by core because they were considered poorly tested and a consensus logic risk. https://github.com/bitcoin/bitcoin/pull/2610 https://github.com/bitcoin/bitcoin/pull/2610 Of course, the highly skilled 'Bitcoin ABC' aka bcash developers obviously tested these well, with no risk to consensus logic or users funds...

yrro 8y ago
Can we please avoid having HN becoming yet another battleground for Core vs Cash sock puppets to dump their trollish posts?
- akerro 8y ago
  Tell people to stop upvoting these threads, don't tell commenters to stop explaining issues and providing sources.
  - fastball 8y ago
    Eh, I think this belongs here. Heavy moderation is probably good to prevent the BTC/BCH flame wars you'll see on other forums, but the technical differences being introduced between the chains (such as OP_CODES here) are actually very interesting I think.
  - ddtaylor 8y ago
    I thought asking people to upvote or downvote content on HN was against the rules?
    - windows_tips 8y ago
      >Please don't impute astroturfing or shillage. That degrades discussion and is usually mistaken. If you're worried about it, email us and we'll look at the data. >Please don't complain that a submission is inappropriate. If a story is spam or off-topic, flag it. Don't feed egregious comments by replying; flag them instead. If you flag something, please don't also comment that you did. >Please don't comment about the voting on comments. It never does any good, and it makes boring reading.

lawlessone 8y ago

>an atomic bet guarantees that the winner will be paid no matter what. How is this possible? is there an Oracle all parties agree to trust? edit:i see how this can work for some sort of bet where the result is calculated on the blockchain itself but outside of that?

zilchers 8y ago
It relies on the parties to take an action (that they are both incentivized to take in order to see if they won). This is similar to atomic swaps - they setup a time boxed window when people must take an action. If one of the parties fails to act in time, they will, in fact, lose their coins.

nwah1 8y ago

Just so we're clear, we're talking about a virtual coin flip here, right? Anything else would require trust. Even if you tried to use an API that checked the scores of a sporting event.

detaro 8y ago
yes, it's just a coin flip.
- lawlessone 8y ago
  Now i'm wondering, what is the ratio of odd to even outputs when calculating this? are they perfectly even or is one more likely for each flip?
tylersmith 8y ago
The example is a coin flip but it could be any random based game by using a different algorithm than "number mod 2". You're correct that it can't act on real world data.
- nwah1 8y ago
  Could this be modified to support, say, a chess game?
  - tylersmith 8y ago
    Chess doesn't have any random element so it wouldn't need this kind of system. You could implement card games and board games that do have randomness like candyland. You could implement chess with only movement commitments and no atomic fair random number generation.
    - detaro 8y ago
      Some aspects of it would be interesting for non-random games too, e.g. the payout if one player stops submitting moves, verifying who won, ..

Immune 8y ago

This is similar to https://github.com/Jfaler/Bitcoin-Casino https://github.com/Jfaler/Bitcoin-Casino

josu 8y ago

The interesting thing about this is that all the logic happens onchain. This is why OP mentions that this is the first truly decentralized bet of this kind, because everything is happening on top of the Bcash decentralized protocol. TL;DR: A very simple smart contract running on the Bcash network.

DennisP 8y ago

I didn't realize this was possible on Bitcoin Cash. Here's a similar idea coded for Ethereum: https://www.blunderingcode.com/gamble-channels-fast-verifiable-off-chain-gambling/ https://www.blunderingcode.com/gamble-channels-fast-verifiab... This uses a chain of hashes so you can make a single commitment for lots of bets, and an off-chain payment channel.

grover_hartmann 8y ago

bcash is trash. https://www.youtube.com/watch?v=oCOjCEth6xI https://www.youtube.com/watch?v=oCOjCEth6xI