Bitcoin Blockchain Forked By Backward-Compatibility Issue 351
New submitter jhantin writes "The Bitcoin blockchain has forked due to a lurking backward-compatibility issue: versions older than 0.8 do not properly handle blocks larger than about 500k, and Slush's pool mined a 974k block today. The problem is that not all mining operations are on 0.8; blocks are being generated by a mix of several different versions of the daemon, each making its own decision as to which of the two forks is preferable to extend, and older versions refuse to honor or extend from a block of this size. The consensus on #bitcoin-dev is damage control: miners need to mine on pre-0.8 code so the backward-compatible fork will outgrow and thus dominate the compatibility-breaking one; merchants need to stop accepting transactions until the network re-converges on the backward-compatible fork of the chain; and average users can ignore the warning that they are out of sync and need to upgrade."
Turns out there's an approximately 512K limit to atomic updates in Berkeley DB which were used by versions prior to 0.8. 0.8 uses a new database, allowing blockchains that old versions won't accept to be created.
Re:For those, like me, reading this and saying wtf (Score:4, Interesting)
It's a new fiat currency (ie. it exists because someone says it exists).
There's no reason why you, I and a bunch of our friends can't get together and say "Right, we'll use this new currency called DollarPounds, we'll use a spreadsheet to keep track of who has how many and they're exchangeable for US$ at a rate of US$1 = $£1" but the only way a fiat currency can possibly work is if you have enough people who will use it.
The idea of Bitcoin is it's a currency that doesn't require a central bank to produce more money. Instead, Bitcoins are "mined" (ie. brought into existence) through means of a mathematical algorithm that generates a verifiable block of numbers. The algorithm is designed to get harder as more bitcoins are mined. Meaning that the rate at which Bitcoins can be mined slows down eventually reaching the point where no more can be mined.
On the one hand, this resolves the "Leaves as currency" inflation problem in the Restaurant at the End of the Universe by creating artificial scarcity. On the other, they've done too good a job - as soon as it becomes impossible - or even impractical - to mine further bitcoins, the currency is likely to become subject to massive deflation. We know what happens when a currency undergoes massive deflation - Germany in the 1930's or, more recently, Zimbabwe happens.
FWIW, my view is it's probably best viewed from a distance with an air of morbid curiosity.
Re:Gobble bobble wobblywob? (Score:4, Interesting)
So if I want to buy a chewing gum with BC, every BC user would neet to create a record of that transaction?
No, every user who wants to be able to check that transactions are valid needs to create a record of it. In the event of the network becoming too large, scaling would likely happen by service providers offering to validate transactions on behalf of customers for a small fee, thus relieving customers of the need to keep a copy of the transaction list. Anyone who wants to set up such a service provider could do so with relative ease.
If this becomes too hard to manage, a further simplification can be made: it would be entirely possible to use a system that summarises the block history list, so that you only have to hold (e.g.) the last few months worth of transactions. Of course, you'd have to trust your source of summaries, but at the moment we have to trust our banks and the credit card processing companies, so we're used to trusting people like this.
What makes bitcoin not scalable on the level of a real currency is the fact that the system is designed so that there can never be more than 21 million of them. OK, they can be subdivided, but even assuming you subdivide them to their technical limit, if the amount of money represented by BTC ever reaches the scale of the amount of USD that was in circulation as of 2008, that would be equivalent to the smallest possible unit of exchange being around 30c. Over time, this figure would increase. And as bitcoin can be lost (e.g. by data loss without backup, owners dying without a record of their passphrases, or simply by people forgetting they own them) and once lost can never be recovered (except by very expensive cryptographic key cracking exercises), the number in circulation is doomed to drop over time. This will merely exacerbate the problem.
Re:Ooh, exciting! (Score:2, Interesting)
You can be a pauliac and still think deflationary currencies are a bad idea. The true blue ones are investing in gold, not BTC. It has substance.
Re:Ooh, exciting! (Score:2, Interesting)
Re:Ooh, exciting! (Score:1, Interesting)
Where do you idiots come from? Ayn Rand didn't die in any sort of poverty, her books are STILL best-sellers on Amazon 60 years after they were first published. She never relied on the state for income (or remotely needed to) that's as much of an utter fabrication as the first ridiculous allegation. And given that she was forced to fork over hundreds of thousand of dollars in taxes to pay for (among other things, like wars) a public healthcare system, she had every right to then avail of it.
Re:For those, like me, reading this and saying wtf (Score:4, Interesting)
Not even close.
You can send money now without a trusted 3rd party ... look, I'm transferring you a bajizzillion dollars right this instant in this message! Since you don't need anyone else to verify it, it must be true! Whats that? Bitcoin does require others to verify, it just doesn't have any way to confirm that those others should be trusted either ... my bad.
Email is in no way decentralized. Neither is anything else on the Internet that actually works.
Email DEPENDS on DNS, DNS is most certainly centralized. Both are then delegated to individual organizations to control, but they are in no way decentralized. You fail to understand how things you speak of work.
Email can not replace the post office either. Email can not provide me with a certified legal proof that the recipient received the message. Email'd scans of most objects aren't accepted, though we are getting to the point where we can scan checks and email them if you want to wait extra days for the bank to verify you aren't scamming them. You utterly fail to take into account all the services the USPS offers.
BitCoin solves no problem that were actual problems before BitCoin existed and introduces ones that everyone else in the world resolved via common sense thousands of years ago. You can't makeup a currency without anything backing it of value. Fiat currencies have governments. BitCoin's entire point as you put it is to not have anyone who can back it, brilliant plan.
You BitCoin guys live in a fantasy world. BitCoin is as likely to work properly as pure communism or socialism.
Re:Old news. (Score:5, Interesting)
Is that you Peter? :) I don't know anyone else who would describe the system like that.
Bitcoin is not an O(n^2) network. The total work done by the core nodes is "number of nodes multipled by number of transactions" - that is two very different quantities. It doesn't help the argument to abuse formal notation like that.
Pieter reported today that his optimized secp256k1 implementation can reach 20,000 signature checks per second on a single core. That is a lot better than the generic OpenSSL code was able to manage. Bear in mind that although it sounds scary, all of VISA is only about 10,000 transactions per second. So even if we're generous about our assumptions on number of inputs, CPU load would barely stress a single core. Today. With existing hardware. Disk IO will be the bottleneck for the forseeable future, but we're talking about a working set of a few hundred megabytes today. Even with an order of magnitude growth the entire thing fits in RAM on my puny laptop. And with two orders of magnitude growth it still fits on a pretty average dedicated server.
But Bitcoin will not reach VISA traffic loads today, or this year, or even this decade. By the time it does, dedicating one single computer to being a node will seem a completely trivial investment in order to have full security on the worlds financial system, because let's face it, if Bitcoin is processing tens of thousands of transactions per second then it's well on its way to being exactly that.
Ultimately, Bitcoin is growing fast and will scale up. That is what Satoshi wanted it to be, that is what most of the people actually creating businesses and writing lots of code also want - so if you think that'll make your coins worthless in a few years, I will happily buy them off you.
-Mike Hearn