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The Bitcoin Blocksize: A Summary

rusty.ozlabs.org

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Re: The Bitcoin Blocksize: A Summary

#71

Post by pstrateman »

paulmd wrote: post #61
michaelt wrote: post #56

Earlier quoted context omitted.

If you required each block to be at least 75% full, what's to stop miners padding out the blocks with trivial transactions?

I suppose that's true. Trying to fix that would basically put you in the third case - you need everyone to be working on the same transactions, which are the most significant (greatest transaction fees).

The entire purpose of mining is to enable global consensus.

It's not possible to ensure that all miners are operating on the same transaction set.

Re: The Bitcoin Blocksize: A Summary

#72

Post by pstrateman »

statoshi wrote: post #68
pstrateman wrote: post #49

Earlier quoted context omitted.

> My best guess is that the optimal current block size is somewhat larger than 1 MB. The optimal current block size is without a doubt smaller than 1MB. The two most important metrics for block size limit are node count and miner validation. Node count has been continually dropping for years despite heroic efforts to improve performance in bitcoin core. Miners have been found to be blindly mining blocks in an attempt…

The optimal block size is obviously 0, as these blocks will propagate through the network the fastest, thus lowering the orphan rate to nearly 0, and will require the least resource usage (bandwidth, hard disk space, CPU cycles) for full node operators. ... see what I did there?

The blocksize limit is fundamentally a trade off between capacity and usability.

Too far in either direction is bad.

The evidence strongly supports the argument that the current 1MB limit is too high.

Re: The Bitcoin Blocksize: A Summary

#73

Post by nly »

pstrateman wrote: post #55
nly wrote: post #32

Earlier quoted context omitted.

Federated cryptocurrency isn't new. If you're willing to tie it in to to the traditional banking system then you can build a way more scalable and liberating digital currency than Bitcoin. The incentives just aren't there for banks to do so. It'd be great for us though.

> Federated cryptocurrency isn't new. Links? (seriously I'm interested)

From an NSA presentation on Stefan Brands work in the 90s. He devised an almost perfect cryptographic digital cash system that has all the anonymity and flexibility of cash with the caveat that people would have to be accountable to double spending via a traditional banking system.

https://groups.csail.mit.edu/mac/classes/6.805/articles/mone...

Re: The Bitcoin Blocksize: A Summary

#74

Post by davidgerard »

statoshi wrote: post #69
davidgerard wrote: post #16

Important point about this debate: * There is not the organic transaction growth for this to even be a problem, and there is no evidence there ever will be. Bitcoin's only real-world use case is illicit goods. * Even 20MB blocks would be susceptible to a cheap spam attack like the DDOS "stress test" a few weeks ago. This is the quintessential bikeshed: a fight to the death for insanely low stakes.

> Bitcoin's only real-world use case is illicit goods. You have a lot to learn; I recommend starting here: https://medium.com/@lopp/the-multifaceted-nature-of-bitcoin-... A deeper dive here: https://www.youtube.com/watch?v=IgETC2JMUBI

I know all the blogpost ones. To list a few problems:

* Bitcoin is not better for any of the consumer uses than existing financial systems, and is significantly worse for most.

* the only real-world use that we see happening is illicit goods (and, as noted in imglorp's comment here, the blockchain's utility as prosecution futures makes it not a great idea for that either).

* real-world consumers, who are at the powerless end of the financial power relationship, consider regulation a feature - the only people who consider a lack of regulation a feature are cranks and scammers.

* pretty much nobody actually wants smart contracts. Dr Strangelove is a movie about an unstoppable smart contract going wrong. Both consumers and businesses want the possibility of regulatory interrupt upon a bad deal. The only people who would want smart contracts are businesses looking to screw over customers with no choice (c.f. mandatory arbitration clauses).

Look, assume I know a bit about this stuff and have looked into the brochure version claims in detail. The possibility of a use case isn't sufficient; we've had six years of Bitcoin, and that's been enough time to see most of that blog post list has been tried and failed. You've had six years, it's time to show actual utility.

Also, this is a site for communication using words; expecting someone to watch a YouTube video when you could just write words yourself is probably not effective communication.

Re: The Bitcoin Blocksize: A Summary

#75

Post by davidgerard »

statoshi wrote: post #68
pstrateman wrote: post #49

Earlier quoted context omitted.

> My best guess is that the optimal current block size is somewhat larger than 1 MB. The optimal current block size is without a doubt smaller than 1MB. The two most important metrics for block size limit are node count and miner validation. Node count has been continually dropping for years despite heroic efforts to improve performance in bitcoin core. Miners have been found to be blindly mining blocks in an attempt…

The optimal block size is obviously 0, as these blocks will propagate through the network the fastest, thus lowering the orphan rate to nearly 0, and will require the least resource usage (bandwidth, hard disk space, CPU cycles) for full node operators. ... see what I did there?

Describing what miners are doing already, with no-transaction blocks and not bothering to verify existing blocks?

Re: The Bitcoin Blocksize: A Summary

#76

Post by Paul-ish »

michaelt wrote: post #56
paulmd wrote: post #46

Earlier quoted context omitted.

Classic tragedy of the commons: for everyone as a whole, it's better to process transactions as fast as possible. But with the way incentives are currently structured, it's better for any individual miner to produce an empty block that propagates faster. Or in other words, to process transactions as slowly as possible. There's two ways you can fix the incentives. One would be to kill the block reward. You don't proce…

If you required each block to be at least 75% full, what's to stop miners padding out the blocks with trivial transactions?

I don't think there would be reason to, except in protest perhaps. 750Kb size block is 750Kb no matter what transactions make up the block; whos transactions go into a block wouldn't change propagation time. Miners would rather take other peoples' transactions if forced to take transactions at all. That way they get the fees.

Re: The Bitcoin Blocksize: A Summary

#77

Post by Paul-ish »

pstrateman wrote: post #71
paulmd wrote: post #61

Earlier quoted context omitted.

I suppose that's true. Trying to fix that would basically put you in the third case - you need everyone to be working on the same transactions, which are the most significant (greatest transaction fees).

The entire purpose of mining is to enable global consensus. It's not possible to ensure that all miners are operating on the same transaction set.

I think Andresen's O(1) block propagation proposal[0] requires exactly that. I'm not sure if he has worked out the details though.

[0]:https://gist.github.com/gavinandresen/e20c3b5a1d4b97f79ac2

Re: The Bitcoin Blocksize: A Summary

#78

Post by pstrateman »

nly wrote: post #73
pstrateman wrote: post #55

Earlier quoted context omitted.

> Federated cryptocurrency isn't new. Links? (seriously I'm interested)

From an NSA presentation on Stefan Brands work in the 90s. He devised an almost perfect cryptographic digital cash system that has all the anonymity and flexibility of cash with the caveat that people would have to be accountable to double spending via a traditional banking system. https://groups.csail.mit.edu/mac/classes/6.805/articles/mone...

>the caveat that people would have to be accountable to double spending via a traditional banking system.

If the systems security is ultimately based on a reputation model then the system is just as secure as the existing banking system.

Re: The Bitcoin Blocksize: A Summary

#79

Post by pstrateman »

Paul-ish wrote: post #77
pstrateman wrote: post #71

Earlier quoted context omitted.

The entire purpose of mining is to enable global consensus. It's not possible to ensure that all miners are operating on the same transaction set.

I think Andresen's O(1) block propagation proposal[0] requires exactly that. I'm not sure if he has worked out the details though. [0]: https://gist.github.com/gavinandresen/e20c3b5a1d4b97f79ac2

Gavin relies on the transactions miners are working on being close to the same, but not exactly.

An easy way to understand the proposal is to think about it in terms of forward error correction.

The design is an improvement over the existing relay network to compactly encode transactions which are not yet fully relayed.

In practice the improvement is very small.

Information on the existing relay network is available here http://bitcoinrelaynetwork.org/

Re: The Bitcoin Blocksize: A Summary

#80

Post by nly »

pstrateman wrote: post #78
nly wrote: post #73

Earlier quoted context omitted.

From an NSA presentation on Stefan Brands work in the 90s. He devised an almost perfect cryptographic digital cash system that has all the anonymity and flexibility of cash with the caveat that people would have to be accountable to double spending via a traditional banking system. https://groups.csail.mit.edu/mac/classes/6.805/articles/mone...

>the caveat that people would have to be accountable to double spending via a traditional banking system. If the systems security is ultimately based on a reputation model then the system is just as secure as the existing banking system.

Which is fine, because the global banking system basically depends on double spending through loans (fractional reserve). If you double spend (spend more than you have), you accumulate a collectable debt and face legal consequences if you don't pay.

There's no way around this under Brands system, someone has to hold the keys to mint new currency, although it can be federated in the sense than every bank, store, or even person, could have their own issue.

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