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Alternate cryptocurrencies => Altcoin Discussion => Topic started by: Abiky on December 27, 2019, 11:15:32 PM



Title: How safe are Zero-Confirmation transactions (especially in BCH)?
Post by: Abiky on December 27, 2019, 11:15:32 PM
Does anyone know how safe are Zero-Confirmation transactions (0-conf) in chains like Bitcoin Cash and Dash? I've seen how these cryptocurrencies are promoting these kind of transactions that are claimed to be suitable for worldwide commerce. Merchants in the mainstream world might be able to accept these cryptocurrencies with ease (unlike Bitcoin and Ethereum). However, it's yet to be seen the level of security 0-conf transactions would provide since both chains (BCH and Dash) are smaller than Bitcoin. This would allow anyone to perform a 51% attack with ease, greatly putting at risk the underlying Blockchain network.

I'm just curious to know more about this, as it could prove to be a game changer and a better alternative (perhaps?) to the Lightning Network. This solution is experimental on the BCH blockchain (as far as I know), while Dash has been using it since it launched back in 2014 (with its InstantSend) feature. The latter claims to have achieved protection against 51% attacks with the new "Chainlocks" feature. But so far, there hasn't been a security audit that would tell us if this is safe for everyday commerce.

Any thoughts? :)


Title: Re: How safe are Zero-Confirmation transactions (especially in BCH)?
Post by: Luigi on January 29, 2020, 05:32:11 PM
Hi Abiky,

- first things first. Don't accept a 0-conf transaction if its value is high. Simply wait for some blocks to role by.
- If the tx value is of casual size there's no need whatsoever to wait for any confirmation on BCH. Rollbacks hardly happen. You can check one of many pages doing statistics on it.
- It is not an experimental or new solution on Bitcoin Cash. It was already used on Bitcoin before Bitcoin Core activated Replace-By-Fee (RBF). Thus it is a well tested on Bitcoin in general.
- RBF undermines 0-conf when the blocksize is limit and demand is high. This situation leads to very long confirmation times and thus provides an easy way to double-spent your coins. BCH don't have this problem, only BTC has it.
- RBF has been deactivated on Bitcoin Cash because 0-conf are very useful. I would suggest to simply try it out yourself with services like BitPay, SatoshiDice or whatever service (there are plenty).

To sum it up: a blockchain has to make the choice between Replace-By-Fee and 0-conf tx. Bitcoin Core goes for RBF, Bitcoin Cash goes for 0-conf.

This is my first post here after more than six years. Let's see how spirits are in here these days.


Title: Re: How safe are Zero-Confirmation transactions (especially in BCH)?
Post by: Abiky on January 31, 2020, 02:24:28 AM
Hi Abiky,

- first things first. Don't accept a 0-conf transaction if its value is high. Simply wait for some blocks to role by.
- If the tx value is of casual size there's no need whatsoever to wait for any confirmation on BCH. Rollbacks hardly happen. You can check one of many pages doing statistics on it.
- It is not an experimental or new solution on Bitcoin Cash. It was already used on Bitcoin before Bitcoin Core activated Replace-By-Fee (RBF). Thus it is a well tested on Bitcoin in general.
- RBF undermines 0-conf when the blocksize is limit and demand is high. This situation leads to very long confirmation times and thus provides an easy way to double-spent your coins. BCH don't have this problem, only BTC has it.
- RBF has been deactivated on Bitcoin Cash because 0-conf are very useful. I would suggest to simply try it out yourself with services like BitPay, SatoshiDice or whatever service (there are plenty).

To sum it up: a blockchain has to make the choice between Replace-By-Fee and 0-conf tx. Bitcoin Core goes for RBF, Bitcoin Cash goes for 0-conf.

This is my first post here after more than six years. Let's see how spirits are in here these days.

Nice observation. I've never thought it that way at first. I guess that I still need a lot to learn, despite being active on the crypto space for some time now. It seems to me that 0-conf transactions suit their purpose best for small transactions (mostly micropayments). Whenever you'd want to grab a cup of coffee or simply buy some donuts in exchange for Bitcoin Cash, you would use 0-conf transactions without doubt. But when you have the need to send large amounts of money for safekeeping, you'd want to wait for at least 6 confirmations just to be safe. 0-conf transactions greatly resembles Bitcoin's Lightning Network transactions where they are confirmed by the merchant instantly. Both blockchain networks (BCH and BTC) have unique techniques for confirming transactions, yet most people are not aware of this.

While I'm not quite fond with the way Bitcoin Cash has been heading towards the path of scalability, it's an interesting cryptocurrency that brings some pizzazz to the original Bitcoin protocol. With due time, we'll be able to determine which coin will be here to stay and which will die in the long run according to mainstream adoption. But so far, Bitcoin is winning the war being the strongest, most widely supported cryptocurrency in the world. Hence, Bitcoin may be all we need to perform micropayments via the Lightning Network without the need to rely on 0-conf transactions that would put the underlying blockchain network at risk. Just my thoughts ;D