Implement hard fork to allow bigger blocks · gavinandresen ...
block size – Todd Blog
32MB max block size bump by dagurval · Pull Request #344 ...
Block size limit controversy - Bitcoin Wiki
Be patient about Classic. It's already a "success" - in the sense that it has been tested, released, and deployed, with 1/6 nodes already accepting 2MB+ blocks. Now it can quietly wait in the wings, ready to be called into action on a moment's notice. And it probably *will* be - in 2016 (or 2017).
The market is conservative but it's also greedy, so it won't act until it absolutely must act, and then it will act with a vengeance - ie, it will act only when blocks start getting full and the network starts getting backlogged and there's no other option: either the network dies (and $5-6 billion USD of investor wealth vanishes into thin air), or investors and businesspeople protect their wealth by making sure we move to bigger blocks. On that fateful day or week (if it occurs between now and January 1, 2018, when Classic "times out"), you can be sure that there will be a massive exodus of nodes to Classic or the other Bitcoin repos supporting 2MB+ blocks. Heck, at that point, even Blockstream/Core will probably stop playing this very dangerous game of "chicken" treading on the edge of the cliff, and finally throw in the towel and say what the hell: if you can't beat 'em, join 'em: In a last-ditch desperate move to remain relevant, they'll come out with some "last minute" olive branch also offering 2MB+ blocks just like all the other repos threatening to hard-fork away from them. Why wouldn't they? After all, everyone already knows that:
The network infrastructure can easily support blocks of 3-4 MB already (proven in multiple empirical surveys of infrastructure capacity and miner sentiment);
The only reason Blockstream/Core is against big blocks is because big blocks require a hard fork, and Blockstream/Core is afraid a hard fork could make them lose their monopoly on the network. But if a hard fork is coming anyways - then they might as well join in the fun (and profit), instead of dying a miserable death on the shorter chainfork.
So now, we can all just sit back and be patient. 2016 is shaping up to be a horrible year for debt-backed fiat , and it's very likely we will see a major flow of cash seeking "safe havens" in hard assets like Bitcoin, physical gold, property, etc. So all Bitcoin needs to do is keep on chugging along, secure and error-free, as it has for the past 7 years - and also be ready for an increase in transactions due to an influx of cash. Bitcoin Classic (and the other 2MB+ clients such as XT and BU) all provide this. And they're all up and running on 1/6 of the nodes already, fully compatible with the Core nodes, all on the same network, working in harmony. This in itself is a major achievement. And the longer people get used to this state of affairs, the more confident they're going to feel about running "alternate" repos. So don't worry if the 2MB+ clients have so far achieved coverage of "only" 1/6 of the network in these first few days (which is still a pretty remarkable achievement in such a short period of time, if you think about it). Over the next 2 years, fiat is going to start to fail - and Bitcoin is now ready to scale. That's all that matters.  For more info about the ongoing collapse of debt-backed fiat, and the tsunami of crises coming in 2016, you can google variations of the following search terms:
Deutsche Bank derivatives Lehman crash
Baltic Dry Index
Negative Interest Rates Policy (NIRP)
new rules for bank bail-ins in Europe effective January 1, 2016
QE - Quantitative Easing
etc. Also: Recall that the last time debt-backed fiat started to fail was right after the US presidential election of 2008 - around November 2008. This suggests an interesting theory: the powers-that-be sweep all the dirt under the rug during the 8 years of the US president's typical two 4-year terms in office. And then, at the end of those 8 years, all the dirt comes out again - around November, once the new president has been elected and the old president is a "lame duck". So, if this theory is correct, we can expect to see a lot of financial "dirt" getting exposed late in 2016 - just like it happened in late 2016 (when Timmy Geithner ran to Congress saying there would be "blood in the streets" if they didn't immediately give Wall Street 700 billion USD in freshly printed debt-backed fiat cash - which eventually ballooned to around 21 trillion USD since then). And finally: The halvening. It's scheduled for around August 2016. So in order for miners to maintain their current level of profits, they would want the price to double around then. Which means that volume (transactions on the blockchain) will also have to double around then. We have already seen (during 2011-2014) that when price and volume are unconstrained by any artificial limit on the blocksize, they have tended to march in lockstep together, tightly correlated:
This graph shows Bitcoin price and volume (ie, blocksize of transactions on the blockchain) rising hand-in-hand in 2011-2014. In 2015, Core/Blockstream tried to artificially freeze the blocksize - and artificially froze the price. Bitcoin Classic will allow volume - and price - to freely rise again.
Classic and several other 2MB+ clients (BU, XT) are already humming along quietly and compatibly on the network;
Debt-backed fiat is starting to show major warning signs of cracking - and this time, it'll be worse than 2008 (Deutsche Bank collapsing would be 5x the size of Lehman; private central banks have all shot their wad with the last 8 years of QE and 25% of the world's GDP now under NIRP; new rules are in place to do bail-ins robbing depositors instead of bail-outs robbing taxpayers, etc.);
Miners will need Bitcoin price (and hence Bitcoin transaction volume - aka blocksize) to roughly double around the halvening; and
The 8-year term of the current US president is about to end.
And all these "interesting" events are scheduled for later this year! So fasten your seatbelts, batten down the hatches, make sure your coins are secure (or ready to trade, if you're the adventurous type), and get out your popcorn: it's going to be a bumpy (but possibly very profitable) ride - if you play your cards right.
Dr Peter R. Rizun, managing editor of the first peer-reviewed cryptocurrency journal, is an important Bitcoin researcher. He has also been attacked and censored for months by Core / Blockstream / Theymos. Now, he has now been *suspended* (from *all* subreddits) by some Reddit admin(s). Why?
Dr. Peter R. Rizun is arguably one of the most serious, prominent, and promising new voices in Bitcoin research today. He not only launched the first scientific peer-reviewed cryptocurrency journal - he has also consistently provided high-quality, serious and insightful posts, papers and presentations on reddit (in writing, at conferences, and on YouTube) covering a wide array of important topics ranging from blocksize, scaling and decentralization to networking theory, economics, and fee markets - including:
It was of course probably to be expected that such an important emerging new Bitcoin researcher would be constantly harrassed, attacked and censored by the ancien régime of Core / Blockstream / Theymos. But now, the attacks have risen to a new level, where some Reddit admin(s) have suspended his account Peter__R. This means that now he can't post anywhere on reddit, and people can no longer see his reddit posts simply by clicking on his user name (although his posts - many of them massively upvoted with hundreds of upvotes - are of course still available individually, via the usual search box). Questions:
What Reddit admin(s) are behind this reddit-wide banishing of Peter__R?
What is their real agenda, and why are they aiding and abbeting the censorship imposed by Core / Blockstream / Theymos?
Don't they realize that in the end they will only harm reddit.com itself, by forcing the most important new Bitcoin researchers to publish their work elsewhere?
(Some have suggested that Peter__R may have forgotten to use 'np' instead of 'www' when linking to other posts on reddit - a common error which subs like /btc will conveniently catch for the poster, allowing the post to be fixed and resubmitted. If this indeed was the actual justification of the Reddit admin(s) for banning him reddit-wide, it seems like a silly technical "gotcha" - and one which could easily have been avoided if other subs would catch this error the same way /btc does. At any rate, it certainly seems counterproductive for reddit.com to ban such a prominent and serious Bitcoin contributor.)
Why is reddit.com willing to risk pushing serious discussion off the site, killing its reputation as a decent place to discuss Bitcoin?
Haven't the people attempting to silence him ever heard of the Streisand effect?
Below are some examples of the kinds of outstanding contributions made by Peter__R, which Core / Blockstream / Theymos (and apparently some Reddit admin(s)) have been desperately trying to suppress in the Bitcoin community. Peer-Reviewed Cryptocurrency Journal
In case anyone missed it, Peter__R hit the nail on the head with this: "The reason we can't agree on a compromise is because the choice is binary: the limit is either used as an anti-spam measure, or as a policy tool to control fees."
"It's because most of them are NOT Bitcoin experts--and I hope the community is finally starting to recognize that" -- Peter R on specialists vs. generalists and the aptitudes of Blockstream Core developers
It is time to usher in a new phase of Bitcoin development - based not on crypto & hashing & networking (that stuff's already done), but based on clever refactorings of datastructures in pursuit of massive and perhaps unlimited new forms of scaling
Peter__R on RBF: (1) Easier for scammers on Local Bitcoins (2) Merchants will be scammed, reluctant to accept Bitcoin (3) Extra work for payment processors (4) Could be the proverbial straw that broke Core's back, pushing people into XT, btcd, Unlimited and other clients that don't support RBF
"My response to Pieter Wuille on the Dev-List has once again been censored, perhaps because I spoke favourably of Bitcoin Unlimited and pointed out misunderstandings by Maxwell and Back...here it is for those who are interested" -- Peter R
Would implementing a malleability fix and offering LN for BCH be enough for BCH to eventually establish superiority over BTC?
Edit: I should clarify, I mean establish superiority in the eyes of "bigblockers", once storage space and bandwith have advanced to a point where an 8MB block is trivial for block propogation latency and blockchain storage, even to them.
Forgive me for any errors or mistaken assumptions here, I'm still trying to educate myself about all this.
I know there are politics involved, but my understanding is that the BCH vs BTC debate is essentially about on-chain vs off-chain transaction volume scaling.
claims larger blocks would increase block propagation latency, which favors Chinese miners as the majority of hash power lies in China (I don't really grasp the reasoning)
sometimes also claims increasing block size makes running full nodes less realistic, though I'm not sure how much weight is placed on this claim
claims that second layer solutions like LN will be enough to deal with increasing transaction volume
I am curious about understanding the first claim more, but what I'm really interested in is the last claim. I saw that back when he was pushing for 8MB blocks/BitcoinXT with Mike Hearn, Gavin Anderson claimed economic pressure to develop second layer solutions like LN is inevitable, but arises naturally from the need for instant transaction confirmations (faster than the 10-minute block discovery time at least) rather than a transaction volume bottleneck.
This got me thinking, second layer solutions seem like a pre-requisite for Bitcoin (BTC or BCH) transactions to be fast/convenient enough to replace fiat (I would love if someone could explain if 0-conf is a superior alternative to something like LN if we ignore the scaling debate, I just found out about 0-conf today). So now that BCH has "kicked the can down the road" so to speak, is fixing the malleability issue and implementing stuff like LN the next priority? I feel like that would convince a lot of people from the BTC camp to convert, but I could be wrong.
The "Eventually the network will be overwhelmed so don't do anything now" Fallacy
The central banker small blockists will argue that when the network achieves the level of Mastercard or Visa that transactions will no longer fit onto the blockchain. Therefore, the bridge is broken and can never be fixed so do not fix it now or so the reasoning goes. Visa has a daily peak rate of about 4,000 tps (transactions per second) The bitcoin network requires roughly 1mb per block to achieve 4 tps. To achieve 4,000 tps would require 1GB blocks. So clearly the network cannot hold blocks of such size and therefore don't make blocks bigger now. This argument is a fallacy. It misses the possibility that we can maintain the 'bridge' now and then in the future make needed improvements. For example, we can make limited increases in block size now while at the same time we develop things like thinner blocks that help to solve this issue. Most likely, by the time we get to 4,000 tps data storage will be less expensive. Finally, we do not need to necessarily oppose all offchain transactions. There may be a balance, but we don't start by immediately moving all transactions off chain. Currently the entire blockchain fits onto a tiny $10 flash drive. Yes, that's right the networks hash rate is measured in units of Exahash and we are debating about increasing the entire network to around 160GB of data which easily fits on a single hard drive. The 'argument' against reasonably sized blocks is basically a lie. The reason is that they claim larger blocks will centralize the network. Yes, possibly in the limit of infinity that is true, but it is preposterous to apply such an argument to 8mb blocks. Furthermore the act of limiting block size has profound centralization risks. In this case BANKS come in and AGGREGATE and INTERMEDIATE transactions. The Lighting Network is what I am referring to it uses Payment Channels. A "payment channel is essentially a pot of bitcoins, established on the block chain, the split of which can be negotiated by passing messages around outside the Bitcoin network." This is how the lighting network 'works'. It is a CENTRAL BANKER PARADIGM supported by thugs like the ThugMost (Thermus the /bitcoin thug in chief) It is time to start challenging these thugs on their fallacies, a slight understanding of what they are up to is all that is necessary. They are working towards creating a Banker solution while at the same time accusing XT of centralizing the network. There is a word for that its called hypocrite. Edit: fix math error.
I recently wrote a text post Success to the Successful (or: why the moon is not far enough). In that post I explained Success to the Successful, an example of what is know as a system archetype, a recurring pattern that systems often take on. I first came across the idea of system archetypes in the book Thinking in Systems: A Primer by Donella Meadows. I would like to use one chapter of this book to analyse cryptocurrencies, as it provides a convenient basis for comparison. I will focus on Dash and Bitcoin because I think this is the illuminating pair to compare, but I will mention others as they become relevant. Donella Meadows describes a system as a set of things—people, cells, molecules, or whatever—interconnected in such a way that they produce their own behavior over time (p2), and as an interconnected set of elements that is coherently organized in a way that achieves something (p11). Chapter 6 of this book is titled Leverage Points—Places to Intervene in a System. I will work through them in turn, briefly explain each, and use them to analyse cryptocurrencies. With any luck, this will also show ways to synthesise a cryptocurrency, ie consciously choose properties that meet intended goals. The leverage points are presented in reverse order, that is to say, point 12 is the weakest intervention point, and point 1 is the strongest. 12. Numbers—Constants and parameters such as subsidies, taxes standards The essence of this point is that changing the tax rate from 18% to 25% or 13% makes no significant change to the was a system works. Donella Meadows says that numbers are dead last on the list of powerful interventions – diddling with the details, rearranging the deck chairs on the Titanic. This means that it is of no real importance that Bitcoin has a 10 minute average block time, whereas Dash and Litecoin have an average of 2.5 minutes, or that Bitcoin uses SHA256 whereas Litecoin uses scrypt. It also means that the debate between (what is now) Bitcoin Core, XT, and Classic, over whether to have 1, 8, or 2MB blocks, the debate which has stalled Bitcoin development for longer than I can now remember, is over the least important part of the system. Meadows might have also called the block size limit debate in Bitcoin re-arranging deck chairs on the Titanic. 11. Buffers—The size of stabilizing stocks relative to their flows In a bathtub, the tub is a buffer (or stock), whereas the tap and sinkhole are flows. Dash has an interesting type of financial stock with its masternode collateral. A large amount of DASH is held by long-term holders to enable the decentralised masternode network, and acts as a sort of saving account for operators. But Meadows says this is a low-leverage point – whether collateral is specifically 1000 DASH, 100 DASH or 10 DASH is probably not significant. 10. Stock-and-Flow Structures—Physical systems and their nodes of intersection This covers things like plumbing systems and road layouts. What is connected to what can significantly change how a system behaves, as a broken water pipe or a poorly-placed road quickly shows. Cryptocurrencies don't have many significant physical stock and flow structures. The main one that springs to mind is the location of Bitcoin miners near hydroelectric power stations and other renewable power sources. Proof-of-stake mining removes that physical structure, but I won't consider that further as most top cryptocurrencies are proof-of-stake. There is another type of structure, which is informational. This actually comes under the higher-leverage point 6. Information Flows, however I will describe them here, as they are revenant to points in between. Dash has two very powerful structures that Bitcoin lacks. First, Dash has proof-of-stake voting. Dash is able to collect the opinions of masternode operators (ie large stakeholders), and broadcast them in a verifiable way to the entire network. Bitcoin has no comparable system. It is like large BTC holders are each locked in their own room with only shouting loudly as a means of communication, while large DASH holders have internet connections and videoconferencing. Second, Dash voting forms part of its treasury system, and controls a flow of money to development projects, which covers all activities that Dash needs. It can increase or decrease these flows at will. Bitcoin development is funded out of deep pockets, and is not necessarily driven by what holders want (as the previous structure is missing). In my mind I see this as a kind of hybrid structure: while technically it is informational (cryptocurrency money is pure information), it behaves in many ways like a flow of gold coins. 9. Delays—The lengths of time relative to the rates of system changes Delays are the time it takes for one part of a system to react to another. They are the source of oscillations. Business suffers natural booms and busts because (for one reason), the time it takes to build up a business, means that by the time it is fully operational, the market may be oversaturated, and some will be forced to close down. Delays that are too short cause overcompensation, common on car dealer forecourts that routinely over- or under-order new stock. On a shorter scale, this is the source of flash-crashes in the stock market. Long delays make long-term planning impossible, for example building the correct number of power plants. Mining hardware is extremely sensitive to delay – planning R&D and installation of mining hardware is fraught with uncertainty due to the long time scales involved. Dash has enormously reduced one kind of delay: consensus formation. Thanks to the structure explained above, it is possible within hours or days to establish consensus of opinion among masternode operators, holding some together some 60% of the currency. For example the 2MB-blocksize proposal was resolved in a few hours. What Donella Meadows describes as diddling with the details was resolved as quickly as such a triviality should be. 8. Balancing Feedback Loops—The strengths of the feedbacks relative to the impacts they are trying to correct A balancing loop is a structure that tries to correct a system that strays from its goal. For example: a thermostat keeping a room at a comfortable temperature; democratic voting keeping a political party from runaway despotism. Balancing loops are important because reinforcing loops are very powerful, and can throw a system out of control, like a steam engine running faster and faster until it explodes. Thanks to its treasury system, Dash has a unique balancing feedback loop: the masternode network can cut funding to any project at will. That means that if – say – the Dash Core team adopted the same 1MB block size policy as Bitcoin Core, in defiance of the previous vote, the masternode network can bring the system back into control by cutting funding to Dash Core. This would not be the end of the matter (another Core team would be required to replace them), but it would start to resolve the problem with a much lower delay. 7. Reinforcing Feedback Loops—The strength of the gain of driving loops This was the topic of the earlier post Success to the Successful (or: why the moon is not far enough), so I would suggest reading that for more detail, as I believe it is a distinguishing feature of Dash among top cryptocurrencies today. To summarise, Dash has a loop where wise masternode voting funds successful projects, which increase the utility of Dash, which increases the price of DASH, which increases the value of the monthly development budget, which increases Dash's capacity to fund successful projects. Bitcoin does not have this loop: a rising price of BTC does not enable Bitcoin to develop itself more successfully, because development is not paid for with BTC, and it does in any case not have the structure to direct funds based on past success. Dash is inherently more able to develop itself than Bitcoin; it is already developing faster, and its development is accelerating thanks to this loop. 6. Information Flows—The structure of who does and does not have access to information This is covered under 10. Stock-and-Flow Structures to make the flow of this post easier to read. But note that Meadows considered Information Flows as higher-leverage points, higher even than Balancing Feedback Loops and Reinforcing Feedback Loops. 5. Rules—Incentives, punishments, constraints This covers everything from the physical laws of nature, through codes of laws enforced by courts, to the rules of trivial board games or casual agreements between friends. Cryptocurrencies have some very hard rules. For example, to spend any BTC or DASH etc, you must be able to sign a valid transaction transferring the money from you to someone else. No amount of begging or pleading will sway the laws of cryptography, any more than begging or pleading can change the force of gravity. The rules of the cryptocurrency block reward determine the incentives of participants in a cryptocurrency. Bitcoin allocates 100% of the block reward to the miner of that block: there is a very strong incentive to mine Bitcoin blocks. However, there is no corresponding incentive for running a Bitcoin node. By splitting the block reward 45% to miners and 45% to masternode operators, Dash has ~4500 masternodes to Bitcoin's ~5500 nodes, despite the currency having a market cap somewhere around 1% of Bitcoin's. Also, Bitcoin has a balancing loop, whereby the more popular Bitcoin becomes, the higher the cost of running a node becomes, and so the lower the net incentive. Only companies and individuals who need to verify every transaction will run a Bitcoin node; with Dash, people will also run nodes because they are paid to do so. One area where Dash is perhaps lacking in this section is punishments. Dash has an incentive that people are paid to do projects to develop Dash, and funding can be withdrawn if they fail to deliver, but they are not punished if they deceive or defraud. As Donella Meadows put 5. Rules quite high up the list, this suggests that adding punishments to negligently managed or fraudulent development projects might be a high-leverage intervention. Meadows says that power over rules is real power. Who gets to decide the rules of a blockchain, decides the fate of a cryptocurrency. Who in Bitcoin, and who in Dash, decides whether blocks will be only 1MB in size, or whether they can be larger? In Dash, this is transparent, bearing in mind the complexities we considered earlier. In Bitcoin, it is considerably less so. 4. Self-organisation—The power to add, change, or evolve system structure This covers evolution, the adaptation of an immune system, ants building a hive, DNA building an ant, members of a society agreeing on its laws. This point is key why capitalism is superior to communism at generating economic development: the minds of everyone working as an entrepreneur, able to startup up and shut down businesses as they sense real demand, will always outpace the abilities of a central planner with limited information and limited capacity to process it. Simply, it creates a bigger, more adaptable brain out society, a more powerful mind to design and provide infrastructure, goods and services. Dash has a layer of self-organisation at a higher level than businesses running on the blockchain. The treasury system works like a circulatory system, providing money to its DAO employees like nutrition to vital functions. This enables Dash to create development teams, marketing teams, market research teams, R&D teams, forum moderation teams and so on. The treasury lets Dash participants self-organise into a nervous system, and function as a viable, self-sustaining organisation. 3. Goals—The purpose or function of a system The goal of a system is what it tries to achieve. The goal of a thermostat is the temperature it wants to maintain the room at. The goal of a political party is to get elected. The goal of a football team is to win the game. What is the goal of Bitcoin? The Bitcoin whitepaper defines it as a peer-to-peer electronic cash system. What is the goal of Monero? The Monero website defines it as is a secure, private, untraceable currency. Dash? Well, Dash is digital cash – citation needed :) Note that the block size debate in Bitcoin is really a debate over its goal – is it peer-to-peer cash, or is it a digital settlement layer for a Lightning Network? Dash has a consensus structure to confirm its goal, it has information and money flows to decide and fund its path to its goal, it has balancing loops to keep it in check. Dash has a clear goal; the goal of Bitcoin right now looks simply undefined. It's not clear who is in a position to define it. But Donella Meadows puts Goals way up the list of leverage points at number 3, so this matters enormously. 2. Paradigms—The mind-set out of which the system–its goals, structures, rules, delays, parameters–arises At this point we may be stepping out of the sphere of any one individual cryptocurrency. What do we want as money? Do we want debt-money created by private institutions? Do we want hard money like gold? Do we want to return to peer-to-peer credit? Do we want centrally-planned money, or market-driven money? I won't attempt to answer any questions here. 1. Transcending Paradigms This is the idea to stay unattached, to realise that no one paradigm is true. Maybe the head of a central bank will come to understand the advantages of cryptocurrency systems; maybe a die-hard libertarian will appreciate the positive role regulation and government intervention can have in financial systems. Meadows describes this as to let go into not-knowing. For me it is to accept that everyone has their own mindset and the goals that this entails, and they come to this mindset through experiences no less real or valid than one's own. At this point we have completely escaped the petty squabbling of 1MB vs 2MB blocks, and opened a discussion on what paradigm of money will best suit the needs of the modern world. That is a debate I think not even Donella Meadows would find easy to resolve. — I hope this analysis proves useful to someone. If it has peeked anyone's interested, I wholeheartedly recommend reading the whole of Thinking in Systems, which is both short and accessible to anyone with an inquisitive mind. (Apologies for any errors, I've typed this quickly in a few spare hours)
My response to "Why BitcoinXT Must Never Gain Consensus"
[Here is the article I am discussing. If there are any errors with what I have said, please let me know.] I must disagree with what a lot of this author says. It seems that he either completely misunderstands the forking mechanism or he is deliberately lying. The hard fork will only be activated two weeks after (but no sooner than January 11, 2016) a supermajority (75%) of the mining hashpower is mining with the newest (bitcoinxt) version number. In layman's terms, a supermajority of the miners must agree to this fork before it ever happens. The users and even people who run nodes have absolutely no say in this (although running a BitcoinXT node could be seen by the miners as a market demand for an updated protocol). Since it is the miners who decide, it shouldn't be necessary to delve into the problems this author says will afflict the miners in the case of a hard fork. Miners most likely will not act against their own best interests. But I can say a few things about them anyway. There is supposedly a big concern for the miners in case the blocksize is too big, thinking that they will basically be forced to accept all transactions no matter what. This author didn't mention it explicitly, but that is certainly not true of transactions with no transaction fees at all. A miner gains absolutely nothing by including those. Ultimately the miners will always operate according to profit and loss. They will figure out what works for them and what doesn't and the blocksize is only one factor in those calculations. For example, a big factor for miners is figuring out propagation times. A solved block, if larger than another block solved by another miner at the same time, will most likely lose the "race" to get their block sent out to the rest of the world and accepted by a majority of nodes. A sub-factor of this factor is the bandwidth available to the miner. Long story short, the miners will mine in a way that is good for them. And if something in the protocol makes it more difficult for miners to operate at their current level, then some miners will cease operations until an equilibrium is reached again and some (probably) large amount of hashpower will remain at a profitable level. The author seems almost hostile to the idea of Bitcoin scaling to the level of a worldwide payment network. He makes it sound like a silly notion. But it is my belief that Bitcoin absolutely needs to scale to the level of a worldwide payment network. If it doesn't, then that means there will always be some centralized system economic actors must go through in order to engage in commerce. Speaking of centralized services, one interesting thing about this entire debate is that virtually the only other proposal for "scaling" Bitcoin is the "Lightning Network". Basically, LN isn't planned to be part of the protocol. It is supposedly designed to be its own payment systems with its own nodes and users. Users will be able to facilitate payments to one another over the LN and the LN nodes (or whatever the equivalent of a node is for LN) will use the Bitcoin blockchain as a clearinghouse, basically clearing out many payments in one transaction. Such a clearinghouse will be necessary if the blockchain doesn't scale ahead of the userbase, since small blocks will create a situation where only the large transaction fees will be able to get a transaction through. LN kind of sounds interesting and might have a place in the future of Bitcoin, but it still seems like a centralized service. It sounds like a banking system. I feel that the only way out of the endless cycle of economic disaster is a protocol that literally every person can use, not just a protocol for big players that create centralized services for us. Another silly thing the author brings up is the notion that the Bitcoin XT schedule for blocksizes is undesirable because you won't be able to change it without another fork. Well, if Bitcoin XT is implemented across the protocol, that means a fork happened. Why would another fork be so ludicrous? If it happened once, it will happen again. Additionally, I believe a change in the schedule could be accomplished by a soft fork (at least over a period of two years). If the blocksize becomes 16 MB and people don't want it to go to 32 MB, a different client will be released with a different schedule and miners will decide what they want to do. A similar 75% supermajority consensus could be implemented just like Bitcoin XT. Another point about the cap on the blocksize. A larger cap does not mean that the miners must create blocks that big. If Bitcoin XT "wins" and 8 MB blocks go into effect, the miners can set their own parameters and propagate whatever size of blocks they want below that level. Depending on those factors I spoke about earlier, I am willing to bet that there will be some spontaneous standard for blocksizes across the mining community and it will be lower than the limit. After all, the limit has been 1 MB for a long time but virtually all blocks have been much smaller than that. Larger blocksizes are much harder to spam and fill by black- or white-hat attackers (it has happened before and it will happen again - next month in fact - Bitpay is planning a spam attack). In fact, an 8 MB block wouldn't just be 8 times harder to attack than a 1 MB block. Here is why: If 1 MB blocks are usually halfway filled (500 KB) with normal transactions, a spammer must fill the other half to spam the network (roughly the same resources spent by the rest of the community). With 8 MB blocks, the spammer must fill 7.5 MB (roughly 15 times the resources spent by the rest of the community). I believe the supposed dangers posed by a hard fork aren't really that dangerous. Especially with the way Bitcoin XT only triggers two weeks after a 75% supermajority of mining hashpower adopts the new rules. Everyone will have more than enough warning about the whole thing. It will be a smooth transition. Anyway, those are my thoughts.
How is this different from Bitcoin XT? Also, some other questions.
Why are you guys raising the blocksize limit? Isn't Bitcoin XT doing the same thing? Will this cause glitches/errors if blocks start to vary in size (as the transition occurs)? My Bitcoin knowledge is rusty.
Bitcoin Core 0.13.2 released | Wladimir J. van der Laan | Jan 03 2017
Wladimir J. van der Laan on Jan 03 2017: -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Bitcoin Core version 0.13.2 is now available from: https://bitcoin.org/bin/bitcoin-core-0.13.2/ Or by bittorrent: magnet:?xt=urn:btih:746697d03db3ff531158b1133bab5d1e4cef4e5a&dn;=bitcoin-core-0.13.2&tr;=udp%3A%2F%2Ftracker.openbittorrent.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.publicbt.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.ccc.de%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr;=udp%3A%2F%2Ftracker.leechers-paradise.org%3A6969&ws;=https%3A%2F%2Fbitcoin.org%2Fbin%2F This is a new minor version release, including various bugfixes and performance improvements, as well as updated translations. Please report bugs using the issue tracker at github: https://github.com/bitcoin/bitcoin/issues To receive security and update notifications, please subscribe to: https://bitcoincore.org/en/list/announcements/join/ Compatibility Microsoft ended support for Windows XP on April 8th, 2014, an OS initially released in 2001. This means that not even critical security updates will be released anymore. Without security updates, using a bitcoin wallet on a XP machine is irresponsible at least. In addition to that, with 0.12.x there have been varied reports of Bitcoin Core randomly crashing on Windows XP. It is not clear what the source of these crashes is, but it is likely that upstream libraries such as Qt are no longer being tested on XP. We do not have time nor resources to provide support for an OS that is end-of-life. From 0.13.0 on, Windows XP is no longer supported. Users are suggested to upgrade to a newer version of Windows, or install an alternative OS that is supported. No attempt is made to prevent installing or running the software on Windows XP, you can still do so at your own risk, but do not expect it to work: do not report issues about Windows XP to the issue tracker.
From 0.13.1 onwards OS X 10.7 is no longer supported. 0.13.0 was intended to work on 10.7+,
but severe issues with the libc++ version on 10.7.x keep it from running reliably. 0.13.1 now requires 10.8+, and will communicate that to 10.7 users, rather than crashing unexpectedly. Notable changes Change to wallet handling of mempool rejection When a newly created transaction failed to enter the mempool due to the limits on chains of unconfirmed transactions the sending RPC calls would return an error. The transaction would still be queued in the wallet and, once some of the parent transactions were confirmed, broadcast after the software was restarted. This behavior has been changed to return success and to reattempt mempool insertion at the same time transaction rebroadcast is attempted, avoiding a need for a restart. Transactions in the wallet which cannot be accepted into the mempool can be abandoned with the previously existing abandontransaction RPC (or in the GUI via a context menu on the transaction). 0.13.2 Change log Detailed release notes follow. This overview includes changes that affect behavior, not code moves, refactors and string updates. For convenience in locating the code changes and accompanying discussion, both the pull request and git merge commit are mentioned.
#9293 e591c10 [0.13 Backport #9053] IBD using chainwork instead of height and not using header timestamp (gmaxwell)
#9053 5b93eee IBD using chainwork instead of height and not using header timestamps (gmaxwell)
RPC and other APIs
#8845 1d048b9 Don't return the address of a P2SH of a P2SH (jnewbery)
#9041 87fbced keypoololdest denote Unix epoch, not GMT (s-matthew-english)
#9122 f82c81b fix getnettotals RPC description about timemillis (visvirial)
#9042 5bcb05d [rpc] ParseHash: Fail when length is not 64 (MarcoFalke)
#9194 f26dab7 Add option to return non-segwit serialization via rpc (instagibbs)
Upgrading and downgrading How to Upgrade If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or bitcoind/bitcoin-qt (on Linux). Downgrade warning Because release 0.10.0 and later makes use of headers-first synchronization and parallel block download (see further), the block files and databases are not backwards-compatible with pre-0.10 versions of Bitcoin Core or other software:
Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or other programs. Reindexing using earlier versions will also not work anymore as a result of this.
The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support. If you want to be able to downgrade smoothly, make a backup of your entire data directory. Without this your node will need start syncing (or importing from bootstrap.dat) anew afterwards. It is possible that the data from a completely synchronised 0.10 node may be usable in older versions as-is, but this is not supported and may break as soon as the older version attempts to reindex. This does not affect wallet forward or backward compatibility. There are no known problems when downgrading from 0.11.x to 0.10.x. Important information Transaction flooding At the time of this release, the P2P network is being flooded with low-fee transactions. This causes a ballooning of the mempool size. If this growth of the mempool causes problematic memory use on your node, it is possible to change a few configuration options to work around this. The growth of the mempool can be monitored with the RPC command getmempoolinfo. One is to increase the minimum transaction relay fee minrelaytxfee, which defaults to 0.00001. This will cause transactions with fewer BTC/kB fee to be rejected, and thus fewer transactions entering the mempool. The other is to restrict the relaying of free transactions with limitfreerelay. This option sets the number of kB/minute at which free transactions (with enough priority) will be accepted. It defaults to 15. Reducing this number reduces the speed at which the mempool can grow due to free transactions. For example, add the following to bitcoin.conf:
More robust solutions are being worked on for a follow-up release. Notable changes Block file pruning This release supports running a fully validating node without maintaining a copy of the raw block and undo data on disk. To recap, there are four types of data related to the blockchain in the bitcoin system: the raw blocks as received over the network (blk???.dat), the undo data (rev???.dat), the block index and the UTXO set (both LevelDB databases). The databases are built from the raw data. Block pruning allows Bitcoin Core to delete the raw block and undo data once it's been validated and used to build the databases. At that point, the raw data is used only to relay blocks to other nodes, to handle reorganizations, to look up old transactions (if -txindex is enabled or via the RPC/REST interfaces), or for rescanning the wallet. The block index continues to hold the metadata about all blocks in the blockchain. The user specifies how much space to allot for block & undo files. The minimum allowed is 550MB. Note that this is in addition to whatever is required for the block index and UTXO databases. The minimum was chosen so that Bitcoin Core will be able to maintain at least 288 blocks on disk (two days worth of blocks at 10 minutes per block). In rare instances it is possible that the amount of space used will exceed the pruning target in order to keep the required last 288 blocks on disk. Block pruning works during initial sync in the same way as during steady state, by deleting block files "as you go" whenever disk space is allocated. Thus, if the user specifies 550MB, once that level is reached the program will begin deleting the oldest block and undo files, while continuing to download the blockchain. For now, block pruning disables block relay. In the future, nodes with block pruning will at a minimum relay "new" blocks, meaning blocks that extend their active chain. Block pruning is currently incompatible with running a wallet due to the fact that block data is used for rescanning the wallet and importing keys or addresses (which require a rescan.) However, running the wallet with block pruning will be supported in the near future, subject to those limitations. Block pruning is also incompatible with -txindex and will automatically disable it. Once you have pruned blocks, going back to unpruned state requires re-downloading the entire blockchain. To do this, re-start the node with
-reindex. Note also that any problem that would cause a user to reindex (e.g.,
disk corruption) will cause a pruned node to redownload the entire blockchain. Finally, note that when a pruned node reindexes, it will delete any blk???.dat and rev???.dat files in the data directory prior to restarting the download. To enable block pruning on the command line:
- -prune=N: where N is the number of MB to allot for raw block & undo data.
Modified RPC calls:
getblockchaininfo now includes whether we are in pruned mode or not.
getblock will check if the block's data has been pruned and if so, return an
- getrawtransaction will no longer be able to locate a transaction that has a
UTXO but where its block file has been pruned. Pruning is disabled by default. Big endian support Experimental support for big-endian CPU architectures was added in this release. All little-endian specific code was replaced with endian-neutral constructs. This has been tested on at least MIPS and PPC hosts. The build system will automatically detect the endianness of the target. Memory usage optimization There have been many changes in this release to reduce the default memory usage of a node, among which:
Accurate UTXO cache size accounting (#6102); this makes the option -dbcache
precise where this grossly underestimated memory usage before
Reduce size of per-peer data structure (#6064 and others); this increases the
number of connections that can be supported with the same amount of memory
Reduce the number of threads (#5964, #5679); lowers the amount of (esp.
virtual) memory needed
Fee estimation changes This release improves the algorithm used for fee estimation. Previously, -1 was returned when there was insufficient data to give an estimate. Now, -1 will also be returned when there is no fee or priority high enough for the desired confirmation target. In those cases, it can help to ask for an estimate for a higher target number of blocks. It is not uncommon for there to be no fee or priority high enough to be reliably (85%) included in the next block and for this reason, the default for -txconfirmtarget=n has changed from 1 to 2. Privacy: Disable wallet transaction broadcast This release adds an option -walletbroadcast=0 to prevent automatic transaction broadcast and rebroadcast (#5951). This option allows separating transaction submission from the node functionality. Making use of this, third-party scripts can be written to take care of transaction (re)broadcast:
Send the transaction as normal, either through RPC or the GUI
Retrieve the transaction data through RPC using gettransaction (NOT
getrawtransaction). The hex field of the result will contain the raw hexadecimal representation of the transaction
The transaction can then be broadcasted through arbitrary mechanisms
[Meta] Re: Bitcoin Core 0.13.2 released | Luke Dashjr | Jan 07 2017
Luke Dashjr on Jan 07 2017: I don't think release announcements are really appropriate for the bitcoin-dev mailing list. People who want these can subscribe to the bitcoin-core-dev list and/or the Core announce mailing list. Maybe sending to bitcoin-discuss would also make sense, but not bitcoin-dev... Luke On Tuesday, January 03, 2017 8:47:36 AM Wladimir J. van der Laan via bitcoin- dev wrote:
Bitcoin Core version 0.13.2 is now available from: https://bitcoin.org/bin/bitcoin-core-0.13.2/ Or by bittorrent: magnet:?xt=urn:btih:746697d03db3ff531158b1133bab5d1e4cef4e5a&dn=bitcoin-co re-0.13.2&tr=udp%3A%2F%2Ftracker.openbittorrent.com%3A80%2Fannounce&tr=udp% 3A%2F%2Ftracker.publicbt.com%3A80%2Fannounce&tr=udp%3A%2F%2Ftracker.ccc.de% 3A80%2Fannounce&tr=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr=udp%3A%2F% 2Ftracker.leechers-paradise.org%3A6969&ws=https%3A%2F%2Fbitcoin.org%2Fbin%2 F This is a new minor version release, including various bugfixes and performance improvements, as well as updated translations. Please report bugs using the issue tracker at github: https://github.com/bitcoin/bitcoin/issues To receive security and update notifications, please subscribe to: https://bitcoincore.org/en/list/announcements/join/ Compatibility Microsoft ended support for Windows XP on [April 8th, 2014](https://www.microsoft.com/en-us/WindowsForBusiness/end-of-xp-support ), an OS initially released in 2001. This means that not even critical security updates will be released anymore. Without security updates, using a bitcoin wallet on a XP machine is irresponsible at least. In addition to that, with 0.12.x there have been varied reports of Bitcoin Core randomly crashing on Windows XP. It is [not clear](https://github.com/bitcoin/bitcoin/issues/7681#issuecomment-2174398 91) what the source of these crashes is, but it is likely that upstream libraries such as Qt are no longer being tested on XP. We do not have time nor resources to provide support for an OS that is end-of-life. From 0.13.0 on, Windows XP is no longer supported. Users are suggested to upgrade to a newer version of Windows, or install an alternative OS that is supported. No attempt is made to prevent installing or running the software on Windows XP, you can still do so at your own risk, but do not expect it to work: do not report issues about Windows XP to the issue tracker. From 0.13.1 onwards OS X 10.7 is no longer supported. 0.13.0 was intended to work on 10.7+, but severe issues with the libc++ version on 10.7.x keep it from running reliably. 0.13.1 now requires 10.8+, and will communicate that to 10.7 users, rather than crashing unexpectedly. Notable changes Change to wallet handling of mempool rejection When a newly created transaction failed to enter the mempool due to the limits on chains of unconfirmed transactions the sending RPC calls would return an error. The transaction would still be queued in the wallet and, once some of the parent transactions were confirmed, broadcast after the software was restarted. This behavior has been changed to return success and to reattempt mempool insertion at the same time transaction rebroadcast is attempted, avoiding a need for a restart. Transactions in the wallet which cannot be accepted into the mempool can be abandoned with the previously existing abandontransaction RPC (or in the GUI via a context menu on the transaction). 0.13.2 Change log Detailed release notes follow. This overview includes changes that affect behavior, not code moves, refactors and string updates. For convenience in locating the code changes and accompanying discussion, both the pull request and git merge commit are mentioned.
#9293 e591c10 [0.13 Backport #9053] IBD using chainwork instead of
height and not using header timestamp (gmaxwell) - #9053 5b93eee IBD using chainwork instead of height and not using header timestamps (gmaxwell)
RPC and other APIs
8845 1d048b9 Don't return the address of a P2SH of a P2SH (jnewbery)
9041 87fbced keypoololdest denote Unix epoch, not GMT
(s-matthew-english) - #9122 f82c81b fix getnettotals RPC description about timemillis (visvirial) - #9042 5bcb05d [rpc] ParseHash: Fail when length is not 64 (MarcoFalke) - #9194 f26dab7 Add option to return non-segwit serialization via rpc (instagibbs) - #9347 b711390 [0.13.2] wallet/rpc backports (MarcoFalke)
#9292 c365556 Complain when unknown rpcserialversion is specified
(sipa) - #9322 49a612f [qa] Don't set unknown rpcserialversion (MarcoFalke)
#9290 35174a0 Make RelayWalletTransaction attempt to AcceptToMemoryPool
(gmaxwell) - #9295 43bcfca Bugfix: Fundrawtransaction: don't terminate when keypool is empty (jonasschnelli) - #9302 f5d606e Return txid even if ATMP fails for new transaction (sipa) - #9262 fe39f26 Prefer coins that have fewer ancestors, sanity check txn before ATMP (instagibbs)
Tests and QA
#9159 eca9b46 Wait for specific block announcement in p2p-compactblocks
(ryanofsky) - #9186 dccdc3a Fix use-after-free in scheduler tests (laanwj)
#9168 3107280 Add assert_raises_message to check specific error message
Bitcoin Core 0.10.0 released | Wladimir | Feb 16 2015
Wladimir on Feb 16 2015: Bitcoin Core version 0.10.0 is now available from: https://bitcoin.org/bin/0.10.0/ This is a new major version release, bringing both new features and bug fixes. Please report bugs using the issue tracker at github: https://github.com/bitcoin/bitcoin/issues The whole distribution is also available as torrent: https://bitcoin.org/bin/0.10.0/bitcoin-0.10.0.torrent magnet:?xt=urn:btih:170c61fe09dafecfbb97cb4dccd32173383f4e68&dn;=0.10.0&tr;=udp%3A%2F%2Ftracker.openbittorrent.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.publicbt.com%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.ccc.de%3A80%2Fannounce&tr;=udp%3A%2F%2Ftracker.coppersurfer.tk%3A6969&tr;=udp%3A%2F%2Fopen.demonii.com%3A1337&ws;=https%3A%2F%2Fbitcoin.org%2Fbin%2F Upgrading and downgrading How to Upgrade If you are running an older version, shut it down. Wait until it has completely shut down (which might take a few minutes for older versions), then run the installer (on Windows) or just copy over /Applications/Bitcoin-Qt (on Mac) or bitcoind/bitcoin-qt (on Linux). Downgrading warning Because release 0.10.0 makes use of headers-first synchronization and parallel block download (see further), the block files and databases are not backwards-compatible with older versions of Bitcoin Core or other software:
Blocks will be stored on disk out of order (in the order they are
received, really), which makes it incompatible with some tools or other programs. Reindexing using earlier versions will also not work anymore as a result of this.
The block index database will now hold headers for which no block is
stored on disk, which earlier versions won't support. If you want to be able to downgrade smoothly, make a backup of your entire data directory. Without this your node will need start syncing (or importing from bootstrap.dat) anew afterwards. It is possible that the data from a completely synchronised 0.10 node may be usable in older versions as-is, but this is not supported and may break as soon as the older version attempts to reindex. This does not affect wallet forward or backward compatibility. Notable changes Faster synchronization Bitcoin Core now uses 'headers-first synchronization'. This means that we first ask peers for block headers (a total of 27 megabytes, as of December 2014) and validate those. In a second stage, when the headers have been discovered, we download the blocks. However, as we already know about the whole chain in advance, the blocks can be downloaded in parallel from all available peers. In practice, this means a much faster and more robust synchronization. On recent hardware with a decent network link, it can be as little as 3 hours for an initial full synchronization. You may notice a slower progress in the very first few minutes, when headers are still being fetched and verified, but it should gain speed afterwards. A few RPCs were added/updated as a result of this:
getblockchaininfo now returns the number of validated headers in addition to
the number of validated blocks.
getpeerinfo lists both the number of blocks and headers we know we have in
common with each peer. While synchronizing, the heights of the blocks that we have requested from peers (but haven't received yet) are also listed as 'inflight'.
A new RPC getchaintips lists all known branches of the block chain,
including those we only have headers for. Transaction fee changes This release automatically estimates how high a transaction fee (or how high a priority) transactions require to be confirmed quickly. The default settings will create transactions that confirm quickly; see the new 'txconfirmtarget' setting to control the tradeoff between fees and confirmation times. Fees are added by default unless the 'sendfreetransactions' setting is enabled. Prior releases used hard-coded fees (and priorities), and would sometimes create transactions that took a very long time to confirm. Statistics used to estimate fees and priorities are saved in the data directory in the fee_estimates.dat file just before program shutdown, and are read in at startup. New command line options for transaction fee changes:
-txconfirmtarget=n : create transactions that have enough fees (or priority)
so they are likely to begin confirmation within n blocks (default: 1). This setting is over-ridden by the -paytxfee option.
-sendfreetransactions : Send transactions as zero-fee transactions if possible
(default: 0) New RPC commands for fee estimation:
estimatefee nblocks : Returns approximate fee-per-1,000-bytes needed for
a transaction to begin confirmation within nblocks. Returns -1 if not enough transactions have been observed to compute a good estimate.
estimatepriority nblocks : Returns approximate priority needed for
a zero-fee transaction to begin confirmation within nblocks. Returns -1 if not enough free transactions have been observed to compute a good estimate. RPC access control changes Subnet matching for the purpose of access control is now done by matching the binary network address, instead of with string wildcard matching. For the user this means that -rpcallowip takes a subnet specification, which can be
a single IP address (e.g. 126.96.36.199 or fe80::0012:3456:789a:bcde)
a network/CIDR (e.g. 188.8.131.52/24 or fe80::0000/64)
a network/netmask (e.g. 184.108.40.206/255.255.255.0 or fe80::0012:3456:789a:bcde/ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff)
An arbitrary number of -rpcallow arguments can be given. An incoming connection will be accepted if its origin address matches one of them. For example: | 0.9.x and before | 0.10.x | |--------------------------------------------|---------------------------------------| | -rpcallowip=192.168.1.1 | -rpcallowip=192.168.1.1 (unchanged) | | -rpcallowip=192.168.1.* | -rpcallowip=192.168.1.0/24 | | -rpcallowip=192.168.* | -rpcallowip=192.168.0.0/16 | | -rpcallowip=* (dangerous!) | -rpcallowip=::/0 (still dangerous!) | Using wildcards will result in the rule being rejected with the following error in debug.log:
Error: Invalid -rpcallowip subnet specification: *. Valid are a single IP (e.g. 220.127.116.11), a network/netmask (e.g. 18.104.22.168/255.255.255.0) or a network/CIDR (e.g. 22.214.171.124/24).
REST interface A new HTTP API is exposed when running with the -rest flag, which allows unauthenticated access to public node data. It is served on the same port as RPC, but does not need a password, and uses plain HTTP instead of JSON-RPC. Assuming a local RPC server running on port 8332, it is possible to request:
In every case, EXT can be bin (for raw binary data), hex (for hex-encoded binary) or json. For more details, see the doc/REST-interface.md document in the repository. RPC Server "Warm-Up" Mode The RPC server is started earlier now, before most of the expensive intialisations like loading the block index. It is available now almost immediately after starting the process. However, until all initialisations are done, it always returns an immediate error with code -28 to all calls. This new behaviour can be useful for clients to know that a server is already started and will be available soon (for instance, so that they do not have to start it themselves). Improved signing security For 0.10 the security of signing against unusual attacks has been improved by making the signatures constant time and deterministic. This change is a result of switching signing to use libsecp256k1 instead of OpenSSL. Libsecp256k1 is a cryptographic library optimized for the curve Bitcoin uses which was created by Bitcoin Core developer Pieter Wuille. There exist attacks against most ECC implementations where an attacker on shared virtual machine hardware could extract a private key if they could cause a target to sign using the same key hundreds of times. While using shared hosts and reusing keys are inadvisable for other reasons, it's a better practice to avoid the exposure. OpenSSL has code in their source repository for derandomization and reduction in timing leaks that we've eagerly wanted to use for a long time, but this functionality has still not made its way into a released version of OpenSSL. Libsecp256k1 achieves significantly stronger protection: As far as we're aware this is the only deployed implementation of constant time signing for the curve Bitcoin uses and we have reason to believe that libsecp256k1 is better tested and more thoroughly reviewed than the implementation in OpenSSL.  https://eprint.iacr.org/2014/161.pdf Watch-only wallet support The wallet can now track transactions to and from wallets for which you know all addresses (or scripts), even without the private keys. This can be used to track payments without needing the private keys online on a possibly vulnerable system. In addition, it can help for (manual) construction of multisig transactions where you are only one of the signers. One new RPC, importaddress, is added which functions similarly to importprivkey, but instead takes an address or script (in hexadecimal) as argument. After using it, outputs credited to this address or script are considered to be received, and transactions consuming these outputs will be considered to be sent. The following RPCs have optional support for watch-only: getbalance, listreceivedbyaddress, listreceivedbyaccount, listtransactions, listaccounts, listsinceblock, gettransaction. See the RPC documentation for those methods for more information. Compared to using getrawtransaction, this mechanism does not require -txindex, scales better, integrates better with the wallet, and is compatible with future block chain pruning functionality. It does mean that all relevant addresses need to added to the wallet before the payment, though. Consensus library Starting from 0.10.0, the Bitcoin Core distribution includes a consensus library. The purpose of this library is to make the verification functionality that is critical to Bitcoin's consensus available to other applications, e.g. to language bindings such as [python-bitcoinlib](https://pypi.python.org/pypi/python-bitcoinlib) or alternative node implementations. This library is called libbitcoinconsensus.so (or, .dll for Windows). Its interface is defined in the C header [bitcoinconsensus.h](https://github.com/bitcoin/bitcoin/blob/0.10/src/script/bitcoinconsensus.h). In its initial version the API includes two functions:
bitcoinconsensus_verify_script verifies a script. It returns whether the indicated input of the provided serialized transaction
correctly spends the passed scriptPubKey under additional constraints indicated by flags
bitcoinconsensus_version returns the API version, currently at an experimental 0
The functionality is planned to be extended to e.g. UTXO management in upcoming releases, but the interface for existing methods should remain stable. Standard script rules relaxed for P2SH addresses The IsStandard() rules have been almost completely removed for P2SH redemption scripts, allowing applications to make use of any valid script type, such as "n-of-m OR y", hash-locked oracle addresses, etc. While the Bitcoin protocol has always supported these types of script, actually using them on mainnet has been previously inconvenient as standard Bitcoin Core nodes wouldn't relay them to miners, nor would most miners include them in blocks they mined. bitcoin-tx It has been observed that many of the RPC functions offered by bitcoind are "pure functions", and operate independently of the bitcoind wallet. This included many of the RPC "raw transaction" API functions, such as createrawtransaction. bitcoin-tx is a newly introduced command line utility designed to enable easy manipulation of bitcoin transactions. A summary of its operation may be obtained via "bitcoin-tx --help" Transactions may be created or signed in a manner similar to the RPC raw tx API. Transactions may be updated, deleting inputs or outputs, or appending new inputs and outputs. Custom scripts may be easily composed using a simple text notation, borrowed from the bitcoin test suite. This tool may be used for experimenting with new transaction types, signing multi-party transactions, and many other uses. Long term, the goal is to deprecate and remove "pure function" RPC API calls, as those do not require a server round-trip to execute. Other utilities "bitcoin-key" and "bitcoin-script" have been proposed, making key and script operations easily accessible via command line. Mining and relay policy enhancements Bitcoin Core's block templates are now for version 3 blocks only, and any mining software relying on its getblocktemplate must be updated in parallel to use libblkmaker either version 0.4.2 or any version from 0.5.1 onward. If you are solo mining, this will affect you the moment you upgrade Bitcoin Core, which must be done prior to BIP66 achieving its 951/1001 status. If you are mining with the stratum mining protocol: this does not affect you. If you are mining with the getblocktemplate protocol to a pool: this will affect you at the pool operator's discretion, which must be no later than BIP66 achieving its 951/1001 status. The prioritisetransaction RPC method has been added to enable miners to manipulate the priority of transactions on an individual basis. Bitcoin Core now supports BIP 22 long polling, so mining software can be notified immediately of new templates rather than having to poll periodically. Support for BIP 23 block proposals is now available in Bitcoin Core's getblocktemplate method. This enables miners to check the basic validity of their next block before expending work on it, reducing risks of accidental hardforks or mining invalid blocks. Two new options to control mining policy:
-datacarrier=0/1 : Relay and mine "data carrier" (OP_RETURN) transactions
if this is 1.
-datacarriersize=n : Maximum size, in bytes, we consider acceptable for
"data carrier" outputs. The relay policy has changed to more properly implement the desired behavior of not relaying free (or very low fee) transactions unless they have a priority above the AllowFreeThreshold(), in which case they are relayed subject to the rate limiter. BIP 66: strict DER encoding for signatures Bitcoin Core 0.10 implements BIP 66, which introduces block version 3, and a new consensus rule, which prohibits non-DER signatures. Such transactions have been non-standard since Bitcoin v0.8.0 (released in February 2013), but were technically still permitted inside blocks. This change breaks the dependency on OpenSSL's signature parsing, and is required if implementations would want to remove all of OpenSSL from the consensus code. The same miner-voting mechanism as in BIP 34 is used: when 751 out of a sequence of 1001 blocks have version number 3 or higher, the new consensus rule becomes active for those blocks. When 951 out of a sequence of 1001 blocks have version number 3 or higher, it becomes mandatory for all blocks. Backward compatibility with current mining software is NOT provided, thus miners should read the first paragraph of "Mining and relay policy enhancements" above. 0.10.0 Change log Detailed release notes follow. This overview includes changes that affect external behavior, not code moves, refactors or string updates. RPC:
f923c07 Support IPv6 lookup in bitcoin-cli even when IPv6 only bound on localhost
b641c9c Fix addnode "onetry": Connect with OpenNetworkConnection
The block size was initially introduced to stop spam attacks from affecting the network, however those issues have since been mitigated. >> Gavin Andresen and Mike Hearn want you to switch to something called Bitcoin XT or Bitcoin Unlimited or some other fork of Bitcoin that is under unilateral control so that they can centralize Bitcoin to a ... Main article: Bitcoin XT Bitcoin XT was an alternative client that became notorious when it adopted BIP 101, which would direct an increase to 8 MB after both January 11, 2016 has passed and 75% of miners are in support, followed by doubling of the limit every two years with the size increasing linearly within those two year intervals. If I was new to Bitcoin and thinking of starting a Bitcoin-related business, the transaction volume cap would make me seriously reconsider. I think that dynamic makes the 1MB limit really sticky: no increased transaction volume, because anybody sane will look at the 1MB block size and the unwillingness of us to do anything about it and will ... A software patch, Bitcoin XT, has been released which will increase the ‘block’ size, i.e. number of recorded transactions which can be processed at one time. To date, Bitcoin XT has been adopted by 9.5% of the network. But because Bitcoin is open source, any change must be approved by the majority of the network, a device which was ... Bitcoin Core is programmed to decide which block chain contains valid transactions. The users of Bitcoin Core only accept transactions for that block chain, making it the Bitcoin block chain that everyone else wants to use. For the latest developments related to Bitcoin Core, be sure to visit the project’s official website.
The risk of validator centralization, network forking, block scarcity and high energy costs required to mine a block have all been extensively debated with no realistic long-term solutions to date. One of the key arguments against bigger blocks and Bitcoin Unlimited is that a blocksize restriction is needed to create a healthy fee market. ... - XT Nodes - Bitcoin Hashrate ... Must watch talk ... 2. Bitcoin Cash solve the scaling issue to increase bitcoin’s block size 3. Powered block of maximum 8 MB size 4. Bitcoin cash raise this limit of transactions per second 5. Bitcoin Cash has low ... bitcoin blockchain size bitcoin basics bitcoin block bitcoin betting bitcoin b font bitcoin miner.b ... bitcoin day trading bitcoin.d bitcoin xt d bitcoind backup d-wave bitcoin mining Why did your last Bitcoin transaction take so long to confirm? And why are transaction fees higher? Get some answers, and maybe more questions, in this video. Check out our new channel! http ...