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Title: summary of Proof of Work Post by: bitmover on April 13, 2018, 11:09:08 PM In this post, I will explain the basic about Bitcoin Blockchain and Proof of Work, an algorithm that validate transactions and create new blocks (mining), as detailed in Bitcoin whitepaper, by Satoshi Nakamoto (https://bitcoin.org/bitcoin.pdf). This apply also for Ethereum and other similar blockchains that use Proof of Work (PoW).
Please feel free to point out any mistakes, as I had some technical and English doubts while writing it First, we need to understand the concept of hashing, only then we can analyze how blockchain works. What is a Hash? A hash is a cryptographic function that receive an input of any length and generate an output of a fixed length , an alphanumerical sequence. Simply put, it is a bunch of random numbers and letters. This is a great website, it shows how hashing and mining works. You can enter some text there to see how it works. https://anders.com/blockchain/hash.html It is important to note that a hash has a fixed size, no matter how big or small the input is. Any small change in one letter in the input will generate a completely different hash (output). This is important if you have a big data, because all this data can be converted to a small hash, which will work as a fingerprint of that data. Blockchain The idea proposed by Satoshi is to register transactions on a block. When the proof of work solution for that block is found, it is hashed. Each block includes the previous block’s hash, forming a chain of blocks (blockchain), and each additional block reinforcing the ones before it. https://i.imgur.com/THKR7GR.png Because of that process, if any transaction in a past block is changed the output hash will be different. When you make a Bitcoin transaction and you see that you have 5 confirmations, that means that 5 blocks were mined after that transaction. A transaction with 6 confirmations is considered irreversible. Proof of Work In the Blockchain, all transactions are publicly announced to all nodes, as there is no central authority who validate transactions. Proof of Work is an algorithm that rewards participants who solve a cryptographic puzzle in order to validate transactions and create new blocks (this process in known as mining). This puzzle consists in scanning for a value (called Nonce) that when hashed together with thr block data, the hash begins with a number of zeros. https://i.imgur.com/fOGqlOz.png In this website (https://andersbrownworth.com/blockchain/blockchain) you can see how this process works. You can try to find a Nonce that when hashed generates a hash that start with 0000 on your own. You will see that it is hard, unless you are very lucky. And you are going to be lucky twice in row, if you do go to a casino or something like that lol. The difficult in finding that nonce increases exponentially as more zeros are required by the block. Difficult is adjusted every 2016 blocks, based on the average hashrate of those past 2016 blocks, so that 2016 blocks are mined every two weeks. (So a block is mined every 10 minutes) Miners only get their reward if they are mining the longest chain, as it has the greatest processing power invested. If the honest nodes control the majority processing power, the honest chain will always be the longest and will outpace attacker’s chain. To modify a past transaction the attacker would have to redo the PoW of the block and all subsequent blocks, and outpace the honest chain. For this to happen, the attacker’s would need more processing power than the honest chain, also known as 51% attack. Quote from: Satoshi in Bitcoin whipepaper The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. Source: bitcoin whitepaper. Images from: https://nakamotoinstitute.org/bitcoin/ Topic also available in Portuguese (short version) (https://bitcointalk.org/index.php?topic=3309188.msg34537791#msg34537791) and Arabic (by Zwei) (https://bitcointalk.org/index.php?topic=5133395) Title: Re: Proof of Work explained Post by: butka on April 15, 2018, 11:29:40 AM When that block is full of transactions, it is hashed. This is not necessarily true. The block can be hashed even when empty or nearly empty. Miners immediately start to search for a valid hash, even before the block has any transactions. (I guess, the incentive to mine a new block is much larger than to collect the transaction fees!!) This was puzzling me too, but then I understood somewhat more (https://bitcointalk.org/index.php?topic=3258807.msg34078972#msg34078972), thanks to @DannyHamilton. Title: Re: Proof of Work explained Post by: nextpakk on April 15, 2018, 11:54:11 AM Thank you for taking the time to explain this process. I found your explanation to be help. You could have jumped straight into the proof of work definition but leading it with simple explanation of how the blockchain plays into it adds much needed clarity.
Title: Re: Proof of Work explained Post by: bitmover on April 15, 2018, 02:46:52 PM When that block is full of transactions, it is hashed. This is not necessarily true. The block can be hashed even when empty or nearly empty. Miners immediately start to search for a valid hash, even before the block has any transactions. (I guess, the incentive to mine a new block is much larger than to collect the transaction fees!!) This was puzzling me too, but then I understood somewhat more (https://bitcointalk.org/index.php?topic=3258807.msg34078972#msg34078972), thanks to @DannyHamilton. Thank you butka. You showed me a very good post. I will review my explanation later. This is more complicated than I thought. Title: Re: my brief summary on Proof of Work Post by: cellard on April 15, 2018, 06:36:21 PM Quote from: satoshi The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Title: Re: my brief summary on Proof of Work Post by: tromp on April 15, 2018, 09:29:43 PM Proof of Work is an algorithm that rewards participants who solve a cryptographic puzzle... This puzzle consists in scanning for a value (called Nonce) that when hashed, the hash begins with a number of zeros. What you describe here is a specific Proof of Work algorithm known as Hashcash. There are many alternative Proof of Work algorithms not based on hashing, as explained in this article http://cryptorials.io/beyond-hashcash-proof-work-theres-mining-hashing/ Title: Re: my brief summary on Proof of Work Post by: wilwxk on April 16, 2018, 01:16:35 AM So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Yes, the PoW could generate a seriously problem of centralization in the future, but this still is not a valid reason to change/update the PoW, we still need a consensus of what type of the algorithm will work better, an example of this is to change the SHA2 to ShA3, invalidating all of the asics, or change the PoW to PoS, which theoretically fishish with the high centralization. But all of these examples has their problem and nobody has certainty if these changes can really improve the bitcoin. Title: Re: my brief summary on Proof of Work Post by: Wind_FURY on April 16, 2018, 05:55:13 AM Quote from: satoshi The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Cobra has the same concerns. I believe some "Bitcoin oracles" were overreacting when they said that he was compromised when he tweeted about buying some Bitcoin Cash. I personally believe that Bitcoin Cash is good for those people who want to have bigger blocks. But what they should not be doing is claiming that it's the real Bitcoin. Plus there are some interesting proposals in Bitcoin Cash that should be considered by Bitcoin Core in my opinion, like implementing more Opcodes to add more functionality. Title: Re: my brief summary on Proof of Work Post by: bob123 on April 16, 2018, 06:56:22 AM ..or change the PoW to PoS, which theoretically fishish with the high centralization.. I don't think a switch to PoS would decrease the centralization. This would only 'move' the centralization from people (with lots of money) who buy miner and electricity to people (with also tons of money) who stake their coins. It might have a small influence on who is mining 'more' blocks. But overall this is not a 'solution' to the 'centralization problem'. Title: Re: my brief summary on Proof of Work Post by: kaar on April 16, 2018, 07:11:24 AM In the Blockchain, all transactions are publicly announced to all nodes, as there is no central authority who validate transactions. The validation system is called Proof of Work. This paragraph is somewhat misleading. The POW isn't used for validation, it's there to prevent double spending and modification of the chain. Validation of transactions in the block is done via cryptographic signatures and has nothing to do with POW. I would emphasize this more, as it's abit unclear from your post what is the purpose of POW in Bitcoin. Title: Re: my brief summary on Proof of Work Post by: ssgtatn on April 16, 2018, 10:15:19 AM Can you explain about 6 confirmations needed for a transaction to be finalized?
Title: Re: my brief summary on Proof of Work Post by: bitmover on April 16, 2018, 10:30:24 AM In the Blockchain, all transactions are publicly announced to all nodes, as there is no central authority who validate transactions. The validation system is called Proof of Work. This paragraph is somewhat misleading. The POW isn't used for validation, it's there to prevent double spending and modification of the chain. Validation of transactions in the block is done via cryptographic signatures and has nothing to do with POW. I would emphasize this more, as it's abit unclear from your post what is the purpose of POW in Bitcoin. Yeah, I just learned about that reading some posts on some other threads. I will review this text soon. Thank you for your observation. Can you explain about 6 confirmations needed for a transaction to be finalized? It doesn't need 6 confirmations to be finalized.Bust many exchanges and websites will wait for 6 confirmations before accepting it, as a transaction is only considered irreversible with 6 confirmations. Title: Re: my brief summary on Proof of Work Post by: andrew1carlssin on April 16, 2018, 10:50:19 AM Thanks OP for such nice summary ...
While reading about Openpgp protocol[1] it came to my mind ...Regards to blockchain itself (think in terms of data structure) .. ... is the blockchain "data at rest" or "data in transit" ? [1] Quote *** Data at Rest OpenPGP is used to protect both data at rest as well as data in motion. Whereas data at rest refers to data that is stored, e.g., on a hard drive, data in motion refers to data that is transferred, e.g., via HTTP. Thus, an encryption scheme that only protects data in motion, such as TLS, removes the encryption on receipt; the data is only protected on the wire. Another way to think about the difference between data at rest and data in motion is that encryption that protects data at rest protects it in time and space whereas encryption that protects data in motion only protects it in space. Yet another way to think about the difference is that data at rest is to the ~tar~ or ~zip~ tools as data in motion is to HTTP or XMPP. The decision to protect not only data in motion, but also data at rest using the same scheme significantly constrains the solution space. In particular, because data at rest may be accessed asynchronously with respect to the encryption, there is no possibility to negociate parameters on the fly. Consider an encrypted backup. When you encrypt the data, you can only use the strongest encryption that is available at the time of the encryption. When you access the data 10 years later, your implementation needs to support that now old encryption algorithm; there is no way to go back in time and say to your former self, "could you use this implementation instead?" # I don't think 10 year old backups are that relevant. Typically only # the latest snapshot is interesting, which should be fresh. And # backups are not longterm preservation archives for many other # reasons. (marcus) An additional consequence is that upgrading the cryptography becomes very difficult. It is not possible to completely deprecate old algorithms, because old messages (like our backup) still need to be decrypted. Similarly, since people continue to use old software, we often cannot use the latest and greatest encryption scheme, because they might not be able to decrypt the data! Another result of this decision to protect data at rest is that enabling forward secrecy is not possible. Forward secrecy is an oft-lauded encryption property, which prevents old encrypted messages from being decrypted if the private key material is somehow compromised. Forward secrecy works by mutating the key material in time. This scheme is fine if you never need to decrypt old messages (as is typically the case for data transferred via HTTPS, say), but doesn't work at all for data at rest: if you want to decrypt some data a week later, nevermind 10 years later, then you won't be able to if you've destroyed the private key material needed to decrypt it! https://gnupg.org/ftp/people/neal/an-advanced-introduction-to-gnupg/openpgp/openpgp.org Title: Re: my brief summary on Proof of Work Post by: ssgtatn on April 16, 2018, 10:52:12 AM Quote It doesn't need 6 confirmations to be finalized. Bust many exchanges and websites will wait for 6 confirmations before accepting it, as a transaction is only considered irreversible with 6 confirmations. I know only the rule - The longest chain will be the right one. Can you please explain more about "a transaction is only considered irreversible with 6 confirmations." Title: Re: my brief summary on Proof of Work Post by: wilwxk on April 16, 2018, 11:22:17 AM Quote from: bob123 I don't think a switch to PoS would decrease the centralization. I'm not trying to say that will decrease the centralization, but "theoretically", according the most of paper it will (like any other paper about Proof of Storage or DAG say that they are the best protocol). Can you please explain more about "a transaction is only considered irreversible with 6 confirmations." There is no reason for the number '6', its only a number of confirmation adopted by most of the services, because when you have more confirmations, more difficult to the miners reverse the transaction. In truth its very difficult to happen, the attacker needs a big percentage of the total hash rate to reverse the transaction even after only one or two cofirmations, and try to mine again a block to try to build a new longest chain above the old block is not profitable since you are competing with other miners which are already mining the longest chain. You can calcule the probability for a miner to reverse a transaction here: people.xiph.org/~greg/attack_success.html (http://people.xiph.org/~greg/attack_success.html) Title: Re: my brief summary on Proof of Work Post by: cellard on April 16, 2018, 04:21:06 PM So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Yes, the PoW could generate a seriously problem of centralization in the future, but this still is not a valid reason to change/update the PoW, we still need a consensus of what type of the algorithm will work better, an example of this is to change the SHA2 to ShA3, invalidating all of the asics, or change the PoW to PoS, which theoretically fishish with the high centralization. But all of these examples has their problem and nobody has certainty if these changes can really improve the bitcoin. The problem is, the longer you leave this unsolved, the worse it will be. If it is basically impossible changing PoW now, I think it's delusional to think it will happen in the future. I guess we will have to deal with what we have and hope for more competition. PoW will never change... unless the algo gets compromised somehow. Quote from: satoshi The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Cobra has the same concerns. I believe some "Bitcoin oracles" were overreacting when they said that he was compromised when he tweeted about buying some Bitcoin Cash. I personally believe that Bitcoin Cash is good for those people who want to have bigger blocks. But what they should not be doing is claiming that it's the real Bitcoin. Plus there are some interesting proposals in Bitcoin Cash that should be considered by Bitcoin Core in my opinion, like implementing more Opcodes to add more functionality. Cobra made 0 sense. One thing is to point at possible centralization of mining on Bitcoin, then a very different thing is saying "im going to buy some Bitcoin Cash" as if BCash wasn't even more centralized. It's sane to think that he was compromised or bribed in some way to shill BCash, it solves none of the fundamental Bitcoin problems. Title: Re: my brief summary on Proof of Work Post by: ssgtatn on April 17, 2018, 04:42:58 AM There is no reason for the number '6', its only a number of confirmation adopted by most of the services, because when you have more confirmations, more difficult to the miners reverse the transaction. In truth its very difficult to happen, the attacker needs a big percentage of the total hash rate to reverse the transaction even after only one or two cofirmations, and try to mine again a block to try to build a new longest chain above the old block is not profitable since you are competing with other miners which are already mining the longest chain. You can calcule the probability for a miner to reverse a transaction here: people.xiph.org/~greg/attack_success.html (http://people.xiph.org/~greg/attack_success.html) Got it, thank you! However, when I check the tool, with 40% hash-power a group can have more than 50% probability to win over the network. It is not really needed to have enough 51% I guess. Title: Re: my brief summary on Proof of Work Post by: Wind_FURY on April 17, 2018, 05:52:41 AM Quote from: satoshi The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Cobra has the same concerns. I believe some "Bitcoin oracles" were overreacting when they said that he was compromised when he tweeted about buying some Bitcoin Cash. I personally believe that Bitcoin Cash is good for those people who want to have bigger blocks. But what they should not be doing is claiming that it's the real Bitcoin. Plus there are some interesting proposals in Bitcoin Cash that should be considered by Bitcoin Core in my opinion, like implementing more Opcodes to add more functionality. Cobra made 0 sense. One thing is to point at possible centralization of mining on Bitcoin, then a very different thing is saying "im going to buy some Bitcoin Cash" as if BCash wasn't even more centralized. It's sane to think that he was compromised or bribed in some way to shill BCash, it solves none of the fundamental Bitcoin problems. That is not what I meant, sorry. I was saying that LukeDashjr and Cobra have the same concerns about the centralization of mining in Bitcoin, and that some Bitcoiners saying that he is compromised just because tweeted that he was buying some Bitcoin Cash may be overreacting. Refer to this blog, https://medium.com/@CobraBitcoin/an-open-letter-to-the-bitcoin-community-to-change-the-proof-of-work-algorithm-12a6545c20d0 Quote An open letter to the Bitcoin community to change the proof-of-work algorithm I believe Cobra is one of those Bitcoiners who still has his eyes open. Title: Re: my brief summary on Proof of Work Post by: BitcoinNewbie15 on April 22, 2018, 08:50:38 PM Quote from: satoshi The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. So basically, the longest chain is whatever Jihan is pointing his machines at? this is how I see it at the moment, unfortunately. We need more competition in mining, im looking forward to the next decade to see what others have to offer. Right now im with Luke when it comes to paying attention to hashrate distribution, it's a problem... but changing the PoW would be a disaster and kicking the can down the road. We either need proper game changing approach to PoW or simply we need more competition for Jihan's monopoly. Again, I think things will look different during the next decade, im not too pessimistic. Cobra has the same concerns. I believe some "Bitcoin oracles" were overreacting when they said that he was compromised when he tweeted about buying some Bitcoin Cash. I personally believe that Bitcoin Cash is good for those people who want to have bigger blocks. But what they should not be doing is claiming that it's the real Bitcoin. Plus there are some interesting proposals in Bitcoin Cash that should be considered by Bitcoin Core in my opinion, like implementing more Opcodes to add more functionality. Cobra made 0 sense. One thing is to point at possible centralization of mining on Bitcoin, then a very different thing is saying "im going to buy some Bitcoin Cash" as if BCash wasn't even more centralized. It's sane to think that he was compromised or bribed in some way to shill BCash, it solves none of the fundamental Bitcoin problems. Sorry if this is a very dumb question, but can you help me understand the "longest chain" is the valid chain concept? This is something I'm confused about when it comes to bcash, as it is currently the longer chain. Is it because these are two separate coins at this point? Or does the "Longest chain" refer to mined blocks that become orphaned? Title: Re: my brief summary on Proof of Work Post by: bitmover on April 22, 2018, 10:15:47 PM Sorry if this is a very dumb question, but can you help me understand the "longest chain" is the valid chain concept? This is something I'm confused about when it comes to bcash, as it is currently the longer chain. Is it because these are two separate coins at this point? Or does the "Longest chain" refer to mined blocks that become orphaned? Bcash is another coin, no matter how long that chain is. It has nothing to do with bitcoin. Title: Re: my brief summary on Proof of Work Post by: nc50lc on April 23, 2018, 06:53:48 AM Or does the "Longest chain" refer to mined blocks that become orphaned? Bcash is another coin, no matter how long that chain is. It has nothing to do with bitcoin.BitcoinCash and other "Planned Hard Forks" however, got a considerably high amount of nodes to continue their own blockchain. And as bitmover said, it is now a different coin in a different blockchain. <edit: fixed quoted msg> Title: Re: my brief summary on Proof of Work Post by: bob123 on April 23, 2018, 06:53:57 AM Sorry if this is a very dumb question, but can you help me understand the "longest chain" is the valid chain concept? The longest valid chain is the actual blockchain. This is something I'm confused about when it comes to bcash, as it is currently the longer chain. Is it because these are two separate coins at this point? Bcash does follow different consenus rules. They hardforked to a bigger block size. The bcash chain is longer because the difficulty is (and was) way lower while some miner were starting to mine on the bcash chain. Bcash blocks are not valid for the bitcoin chain. Or does the "Longest chain" refer to mined blocks that become orphaned? No, longest valid (meeting all consens rules) chain. Or does the "Longest chain" refer to mined blocks that become orphaned? Yup...No. https://bitcoin.stackexchange.com/questions/5859/what-are-orphaned-and-stale-blocks (https://bitcoin.stackexchange.com/questions/5859/what-are-orphaned-and-stale-blocks) Title: Re: my brief summary on Proof of Work Post by: BEX on April 25, 2018, 06:53:47 AM Yes and Proof of Stake (and Delegated POS) might be a solution to POW, hense Ethereum current move to POS...https://www.blockchains-expert.com/en/proof-of-work-vs-proof-of-stake-2/
Title: Re: my brief summary on Proof of Work Post by: bitmover on April 25, 2018, 11:04:39 AM Yes and Proof of Stake (and Delegated POS) might be a solution to POW, hense Ethereum current move to POS...https://www.blockchains-expert.com/en/proof-of-work-vs-proof-of-stake-2/ Nobody knows when ethereum Casper (pos) will be released. And Casper is not 100% proof of stake, as most blocks will still be pow in the beginning. I see many people saying"a solution to pow" as if pow was a problem and pos was a solution to every problem. Pls still needs to be tested in a great scale blockchain like ethereum. Until then we don't know what to really expect. Title: Re: my brief summary on Proof of Work Post by: DevilOper on April 25, 2018, 11:30:05 AM You can calcule the probability for a miner to reverse a transaction here: people.xiph.org/~greg/attack_success.html (http://people.xiph.org/~greg/attack_success.html) Got it, thank you! However, when I check the tool, with 40% hash-power a group can have more than 50% probability to win over the network. It is not really needed to have enough 51% I guess. I can easily assert the calculation is totally wrong: for one single confirmation the probability to reverse a transaction literally means the probability to 'mine' a block -> is equial to the 'Proportion of hash-power'. Then try to enter the 'Proportion of hash-power' = 0.5 and the 'Number of confirms' = 1. Title: Re: my brief summary on Proof of Work Post by: bob123 on April 25, 2018, 11:35:18 AM I see many people saying"a solution to pow" as if pow was a problem and pos was a solution to every problem. The actual problem with PoW is the used energy. With the rising average temperature and the media comparing BTC's energy usage to countries like denmark, a 'solution' would be handy. Wether PoS can (safely and securely) replace PoW is neither proved nor disproved. It may but also may not be the 'solution'. But if the hashrate (with more miner) and the energy consumption is going to rise further, governments will start cracking down on mining (like already happened in several countries). Title: Re: my brief summary on Proof of Work Post by: bitmover on April 25, 2018, 11:51:13 AM I see many people saying"a solution to pow" as if pow was a problem and pos was a solution to every problem. The actual problem with PoW is the used energy. With the rising average temperature and the media comparing BTC's energy usage to countries like denmark, a 'solution' would be handy. Wether PoS can (safely and securely) replace PoW is neither proved nor disproved. It may but also may not be the 'solution'. But if the hashrate (with more miner) and the energy consumption is going to rise further, governments will start cracking down on mining (like already happened in several countries). I think this is hypocrisy, as Christmas lights consume as much energy. http://www.coindaily.co/2017/12/14/christmas-decorations-consume-as-much-electricity-as-bitcoin-mining/ And how much energy does the whole banking system consumes? Hi much does visa consumes? Nobody knows exactly, while btc mining is easy to point out , as someone who does not understand what bitcoin is mining is just a waste of energy to create some nerd money in a computer. Title: Re: my brief summary on Proof of Work Post by: bob123 on April 25, 2018, 12:23:05 PM I think this is hypocrisy, as Christmas lights consume as much energy. http://www.coindaily.co/2017/12/14/christmas-decorations-consume-as-much-electricity-as-bitcoin-mining/ While you - and any other reader of coindaily.co - know this fact, the majority of people (regardless wether invested in BTC or never heard from BTC before) will hear the comparison between BTC and country X. People still tend to accept christmas lightning (because hey, its christmas) over a mathematically (and technically) proven working form of a decentralised ledger without any influence of a 3rd party. And how much energy does the whole banking system consumes? Hi much does visa consumes? Nobody knows exactly, while btc mining is easy to point out , as someone who does not understand what bitcoin is mining is just a waste of energy to create some nerd money in a computer. If you consider all the energy used in the banking system (not just server uptime) i would assume that its definetely more than the energy consumption of the BTC network (just a personal guess tho). But nobody cares what visa consumes. Visa is a ('necessary') working financial instrument. You won't find the media talking about the enormous effort needed to keep the visa network alive. This is (sadly) the point. Title: Re: my brief summary on Proof of Work Post by: bitmover on April 25, 2018, 01:27:00 PM I think this is hypocrisy, as Christmas lights consume as much energy. http://www.coindaily.co/2017/12/14/christmas-decorations-consume-as-much-electricity-as-bitcoin-mining/ While you - and any other reader of coindaily.co - know this fact, the majority of people (regardless wether invested in BTC or never heard from BTC before) will hear the comparison between BTC and country X. People still tend to accept christmas lightning (because hey, its christmas) over a mathematically (and technically) proven working form of a decentralised ledger without any influence of a 3rd party. And how much energy does the whole banking system consumes? Hi much does visa consumes? Nobody knows exactly, while btc mining is easy to point out , as someone who does not understand what bitcoin is mining is just a waste of energy to create some nerd money in a computer. If you consider all the energy used in the banking system (not just server uptime) i would assume that its definetely more than the energy consumption of the BTC network (just a personal guess tho). But nobody cares what visa consumes. Visa is a ('necessary') working financial instrument. You won't find the media talking about the enormous effort needed to keep the visa network alive. This is (sadly) the point. Well, in my opinion proof of work is not the problem then. He problem is all that misinformation about it and about bitcoin, in a attempt to discredit it to common people, who "cares about global warming", favoring banks and Visa. I think even that proof of work can sponsor renewable energy sources, like solar panels. Any excess energy produced by them can be directed to bitcoin mining, that would make the capital recovery make much faster Title: Re: my brief summary on Proof of Work Post by: DevilOper on April 25, 2018, 01:53:08 PM I suggest you to compare not the overall energy consumption but one per transaction, since the transactions are not the only thing banking system does, and VISA performs much more transactions per day than bitcoin in a year.
Title: Re: my brief summary on Proof of Work Post by: BanishedDemon on June 26, 2018, 08:14:51 PM VISA performs much more transactions per day than bitcoin in a year. Agree , it is worth searching at estimates for a consistent with-transaction power cost because we will examine that price to existing fee structures. it's also a extra tangible way to represent price-for-electricity. simply understanding that total bitcoin mining consumes x quantity of electricity is thrilling, but it's better to discuss how many transactions we're definitely getting for all that power spent. Title: Re: summary on Proof of Work Post by: bitmover on October 31, 2018, 01:50:47 PM Edit:
Fixed images, which were not showing up anymore Title: Re: summary on Proof of Work Post by: Aura on November 03, 2018, 03:09:04 PM This puzzle consists in scanning for a value (called Nonce) that when hashed, the hash begins with a number of zeros. From this line it seems that the only hash input is the nonce. However, from my understanding, all block data is hashed. The only variable in this block of data is the nonce, therefore it can change the hash output. The difficult in finding that nonce increases exponentially as more zeros are required by the block. Difficult is adjusted so that one block is mined every 10 minutes. This sentence would be more clear if you would introduce the frequent term difficulty. Optionally, you can add that the difficulty only changes every 2016 blocks or average two weeks. Despite this, I still find your summary very informative and accurate. Title: Re: summary on Proof of Work Post by: bitmover on November 04, 2018, 12:01:26 PM This puzzle consists in scanning for a value (called Nonce) that when hashed, the hash begins with a number of zeros. From this line it seems that the only hash input is the nonce. However, from my understanding, all block data is hashed. The only variable in this block of data is the nonce, therefore it can change the hash output. The difficult in finding that nonce increases exponentially as more zeros are required by the block. Difficult is adjusted so that one block is mined every 10 minutes. This sentence would be more clear if you would introduce the frequent term difficulty. Optionally, you can add that the difficulty only changes every 2016 blocks or average two weeks. Despite this, I still find your summary very informative and accurate. Thanks, just added your suggestions There are far too many details, and I try to keep this as simple as possible Title: Re: summary on Proof of Work Post by: Aura on November 04, 2018, 10:00:54 PM This puzzle consists in scanning for a value (called Nonce) that when hashed, the hash begins with a number of zeros. From this line it seems that the only hash input is the nonce. However, from my understanding, all block data is hashed. The only variable in this block of data is the nonce, therefore it can change the hash output. The difficult in finding that nonce increases exponentially as more zeros are required by the block. Difficult is adjusted so that one block is mined every 10 minutes. This sentence would be more clear if you would introduce the frequent term difficulty. Optionally, you can add that the difficulty only changes every 2016 blocks or average two weeks. Despite this, I still find your summary very informative and accurate. Thanks, just added your suggestions There are far too many details, and I try to keep this as simple as possible I understand your decision. Keep up the good work! Title: Re: summary on Proof of Work Post by: bitmover on January 22, 2019, 09:00:57 AM I have just moved this topic to beginners and help board. I believe it will fit better here.
I created this when I was reading mastering bitcoin book and learning a lot about BTC Hope it can help newbies Title: Re: summary on Proof of Work Post by: bitmover on September 19, 2019, 05:45:10 PM This topic is also available in Portuguese (short version) (https://bitcointalk.org/index.php?topic=3309188.msg34537791#msg34537791) and Arabic (by Zwei) (https://bitcointalk.org/index.php?topic=5133395), recently translated.
Title: Re: summary on Proof of Work Post by: bitmover on April 08, 2020, 05:32:39 PM Friendly hump
Hood read for new comers who want to learn about bitcoin and how it works, why it expands energy and so on. |
