Blockchain: What Is In A Block?
In my previous article, I tried to described the concept of a blockchain with code. This time, I'll try to describe the structure of a single block. I will use the Bitcoin blockchain to explain blocks, but keep in mind that the concepts will remain more or less the same. It could be useful to read my last article to understand a few things first. A block is a container data structure. In the Bitcoin world, a block contains more than 500 transactions on average. The average size of a block seems to be 1MB ( source ). In Bitcoin Cash ( a hard fork from the Bitcoin blockchain ), the size of a block can go up to 8MB. This enables more transactions to be processed per second. Anyway, a block is composed of a header and a long list of transactions. Let's start with the header. The header contains metadata about a block. There are three different sets of metadata: The previous block hash. Remember that in a blockchain, every block is inherits from the previous block because we use the previous block's hash to create the new block's hash. For every block N, we feed it the hash of the block N-1. Mining competition. For a block to be part of the blockchain, it needs to be given a valid hash. This contains the timestamp, the nonce and the difficulty. Mining is another crucial part of the blockchain technology, but it is outside the scope of this article. The third part is a merkle tree root. This is a data structure to summarize the transactions in the block. And we will leave it at that for now. More on this later. To identify a block, you have a cryptographic hash, a digital signature if you will. This is created by hashing the block header twice with the SHA256 algorithm. For example, this is a block . I will refer to this block as an example for this article. The block header Continue reading >>
How Does The Blockchain Work? (part1)
Ethereum: A Next-Generation Smart Contract and Decentralized Application Platform If youre like many people asking questions like: I have an idea and I want to know if my project is suitable for a blockchain. read these two papers, plus this one - Im looking for investments and I want to know if this token or that token will go up in value read these two papers. I wish you all the best on your journey.and here we go. Well here is a simple explanation that cuts through the hype. Blockchain is a hot topic around the world these days, yet for many, the technology remains an elusive concept. Yet it shouldnt, the concept is simple once you get your head around the architecture and theory of basic crypto economics. When you do have your a Ha moment, the world will never seem the same to you again. This blockchain basics guide is designed to deliver a clear, non-technical introduction to one of the most transformational & misunderstood technologies of our time. If you want to know what blockchain technology is, how it works, and its potential impacts, without all the technical lingo, then this post is for you. Historically, when it comes to transacting money or anything of value, people and businesses have relied heavily on intermediaries like banks and governments to ensure trust and certainty.[ 1 ] Middlemen perform a range of important tasks that help build trust into the transactional process like authentication & record keeping.[ 2 ] The need for intermediaries is especially acute when making a digital transaction. Because digital assets like money, stocks & intellectual property, are essentially files, they are incredibly easy to reproduce. This creates whats known as the double spending problem (the act of spending the same unit of value more than once) which until now Continue reading >>
What Is The Bitcoin Mining Block Reward?
The Bitcoin block reward refers to the new bitcoins distributed by the network to miners for each successfully solved block. Satoshi Nakamoto, Bitcoins creator, set the block reward schedule when he created Bitcoin. It is one of Bitcoins central rules and cannot be changed without agreement between the entire Bitcoin network. The block reward started at 50 BTC in block #1 and halves every 210,000 blocks. This means every block up until block #210,000 rewards 50 BTC, while block 210,001 rewards 25. Since blocks are mined on average every 10 minutes, 144 blocks are mined per day on average. At 144 blocks per day, 210,000 blocks take on average four years to mine. Total circulation will be 21,000,000 coins. Itll be distributed to network nodes when they make blocks, with the amount cut in half every 4 years. first 4 years: 10,500,000 coins next 4 years: 5,250,000 coins next 4 years: 2,625,000 coins next 4 years: 1,312,500 coins etc - Satoshi Nakamoto The block reward is the only way that new bitcoins are created on the network. Satoshi explained this in an early email post in 2009: Coins have to get initially distributed somehow, and a constant rate seems likethe best formula. The block reward creates an incentive for miners to add hash power to the network. The block reward is what miners try to get using their ASICs, which make up the entirety of the Bitcoin network hash rate. ASICs are expensive, and have high electricity costs . Miners are profitable when their hardware and electricity costs to mine one bitcoin are lower than the price of one bitcoin. This means miners can mine bitcoins and sell them for a profit. The more hash power a miner or mining pool has, the greater the chance is that the miner or pool has to mine a block. As miners add more hash rate, more sec Continue reading >>
How Can I Look Up A Transaction Onthe Blockchain?
How can I look up a transaction onthe blockchain? Block Explorers provide a visually appealing and intuitive way to navigate the bitcoin blockchain. Our Block Explorer launched in August 2011, and was created as a way for anyone to study bitcoin transactions, along with a variety of helpful charts and statistics about activity on the network. To look up a bitcoin transaction, users can visit and use the search bar on the upper right to learn more about a particular bitcoin address, transaction hash, or block number by entering it in the search field. Once you click enter, information about your search query will display. Take a look at this transaction we found on the blockchain as an example. Continue reading >>
How Bitcoin Mining Works - Coindesk
In traditional fiat money systems, governments simply print more money when they need to. But in bitcoin, money isn’t printed at all – it is discovered. Computers around the world ‘mine’ for coins by competing with each other. People are sending bitcoins to each other over the bitcoin network all the time, but unless someone keeps a record of all these transactions, no-one would be able to keep track of who had paid what. The bitcoin network deals with this by collecting all of the transactions made during a set period into a list, called a block. It’s the miners’ job to confirm those transactions, and write them into a general ledger. This general ledger is a long list of blocks, known as the 'blockchain'. It can be used to explore any transaction made between any bitcoin addresses, at any point on the network. Whenever a new block of transactions is created, it is added to the blockchain, creating an increasingly lengthy list of all the transactions that ever took place on the bitcoin network. A constantly updated copy of the block is given to everyone who participates, so that they know what is going on. But a general ledger has to be trusted, and all of this is held digitally. How can we be sure that the blockchain stays intact, and is never tampered with? This is where the miners come in. When a block of transactions is created, miners put it through a process. They take the information in the block, and apply a mathematical formula to it, turning it into something else. That something else is a far shorter, seemingly random sequence of letters and numbers known as a hash. This hash is stored along with the block, at the end of the blockchain at that point in time. Hashes have some interesting properties. It’s easy to produce a hash from a collection Continue reading >>
What Is Blockchain Technology? A Step-by-step Guide For Beginners
What is Blockchain Technology? A Step-by-Step Guide For Beginners Angel Investors, Startups & Blockchain developers... Is blockchain technology the new internet? The blockchain is an undeniably ingenious invention the brainchild of a person or group of people known by the pseudonym, Satoshi Nakamoto . But since then, it has evolved into something greater, and themain question every single person is asking is: What is Blockchain? By allowing digital information to be distributed but not copied, blockchain technology created the backbone of a new type of internet. Originally devised for the digital currency , Bitcoin , the tech community is now finding other potential uses for the technology. Bitcoin has been called digital gold, and for a good reason. To date, the total value of the currency is close to $9 billion US. And blockchains can make other types of digital value. Like the internet (or your car), you dont need to know how the blockchain works to use it. However, having a basic knowledge of this new technology shows why its considered revolutionary. So, we hope you enjoy this, what is Blockchain guide. The blockchain is an incorruptible digital ledger of economic transactions that can be programmed to record not just financial transactions but virtually everything of value. Picture a spreadsheet that is duplicated thousands of times across a network of computers. Then imagine that this network is designed to regularly update this spreadsheet and you have a basic understanding of the blockchain. Information held on a blockchain exists as a shared and continually reconciled database. This is a way of using the network that has obvious benefits. The blockchain database isnt stored in any single location, meaning the records it keeps are truly public and easily verif Continue reading >>
What Are Bitcoin Blocks And Bitcoin Confirmations ?
What are Bitcoin Blocks and Bitcoin Confirmations ? Last updated on March 18th, 2015 at 10:43 am Lets say I send you 1 Bitcoin. After a few minutes you see that this transaction has received one confirmation. What does this actually mean? The block chain is built out of blocks. Each new block is a set of new unique Bitcoin transactions that were recently made.So when I broadcasted to the network that I want to send you 1 Bitcoin the transaction went into an unconfirmed transactions pool. Miners entered the unconfirmed transactions pool, took this transaction and others like it, verified they were valid (meaning I actually have the 1 Bitcoin to spend), and grouped them into a block.The new block is set at the top of the blockchain and is considered confirmed. Now miners can move on to build the next block on top of that one. Each time a new block is built it means that the older blocks got confirmed again (since they are checked also in the process). The more confirmations you get, the harder it will be for someone to manipulate the system and remove the block containing this transaction from the wall (or blockchain) since its buried under the other blocks that were confirmed. It is recommended to wait for at least 6 confirmations in order to be 99.9% sure that your transaction wont get canceled this takes roughly 1 hour to achieve. If youre dealing with smaller amounts of money youre probably OK with waiting for just 1 confirmation. Reversing a transaction takes planning, time and effort and a lot of computing power. Most people probably wont go through all of that trouble for a small amount of money. Continue reading >>
What Is A Block/blockchain Explorer?
By: Sudhir Khatwani In: Cryptocurrency Last Updated: A blockchain explorer is a browser for the blockchain, similar to how we have browsers like Mozilla or Google Chrome for internet web pages. All Bitcoin and altcoin users rely heavily on blockchain explorers to track their transactions. But very few users really appreciate the full potential of these explorers. These browsers provide much more valuable information than just tracking of transactions. Note: I will be using the terms blockchain explorer and block explorer interchangeably. They mean the same thing. A block explorer allows you to explore the whole entire blockchain of the platform you are using. But it needs to be noted that you cant use a block explorer for a blockchain it wasnt meant for. For example, you cant track Litecoin transactions with a Bitcoin block explorer. Youll need a Litecoin block explorer for that (like this one . For the sake of explaining things, I will be talking about Bitcoin block explorers, but each blockchain interfaces and functions in the same way with its respective explorer. 1. Blocks Feed Block explorers allow you to explore recently mined blocks on the Bitcoin blockchain. Typically all Bitcoin block explorers provide a live feed of all the blocks that are being added to the blockchain in real time. 2. Transaction Feed Block explorers allow you to explore any transaction in any block that has already been mined and is currently attached to the Bitcoin blockchain. 3. Transaction History Of A Given Address Using a Bitcoin block explorer, you can check the history of any public Bitcoin address and audit how many transactions it has received, its balance, etc. 4. Receiving Address & Change Address Using a Bitcoin block explorer, you can see the Bitcoin receiving address and the B Continue reading >>
If We Lived In A Bitcoin Future, How Big Would The Blockchain Have Tobe?
If we lived in a Bitcoin future, how big would the blockchain have tobe? Lets imagine Bitcoin has accomplished the unthinkable its become the one true currency used for peer-to-peer payments around the world. In this Bitcoin Valhalla, lets imagine that all non-cash payments are conducted with Bitcoin. Instead of credit cards, people whip out their favourite Bitcoin hardware or mobile wallets in coffee shops and hair salons across the world. Just how many of these non-cash payments would there be in this perfect world? Today, non-cash payments account for approximately 522 billion transactions per year worldwide , and that number seems to be increasing in quadratic fashion, meaning itll be a lot bigger by the time we get to Bitcoin Valhalla. Theres no predicting when exactly well get there, so lets imagine that Bitcoin has taken over as the dominant currency today. Where we stand in terms of non-cash transactions across the world, source: worldpaymentsreport.com Now of course, Bitcoin has to make sure its system can accommodate the enormous number of transactions here without bottlenecking. So lets dive into the source code and flick the scalability switch that appeared to be there all along lets increase the size of the block enough to account for our 522 billion transactions. Lets do some napkin math to see just how big our new block is. 522 billion transactions a year translates to 1.4 billion transactions a day. This is equivalent to 9,722,220 transactions every 10 minutes, which coincides with how often blocks are published to the Bitcoin blockchain. Assuming transaction sizes stay around the same size, at 250 bytes , this means that every block would hold about 2.4 gigabytes of data. This transaction volume would generate about 350 gigabytes on the blockchain ever Continue reading >>
Block (bitcoin Block)
Blocks are files where data pertaining to the Bitcoin network is permanently recorded. A blockrecords some or all of the most recent Bitcoin transactions thathave not yet entered any prior blocks. Thus a block is like a page of a ledger or record book.Each time a block is completed, it gives way to the next block in the blockchain.A block is thus a permanent store of records which, once written, cannot be altered or removed. The Bitcoin network witnesses a great dealof transaction activity. Maintaining a record of these transactions helps users track what was paid to and by whom. The transactions executed during a given period of time are recorded into a file called a block. By way of analogy, lets compare ordinarybanking transactions to transactions over the Bitcoin network. A blockchain is like a record of bank transactions whereas a block might bea single transaction confirmation that a bank ATM prints out after you use the machine. In other words, the relationship of block to blockchain is one of part to whole. A block represents the present and contains information aboutitspast and future. Each time a block is completed it becomes part ofthe past and gives way to a new block in the blockchain. The completed block is a permanent record of transactions in the past and the new transactions are recorded in the current one. This way the whole system works in a cycle and data gets permanently stored. Each block comprises records of some or all recenttransactions, and a reference to the block that preceded it. A mathematical problem is linked with each block. Miners are constantly processing and recording transactions as part of the process ofcompeting in a type of race. They race to complete the current block in order to win Bitcoins.When a winning miner is able to solv Continue reading >>
The Mystery Behind Blocktime
Identity Evangelist, Author, Blogger, Developer, Blockchain Enthusiast, Senior Director of Security Architecture at WSO2, Apache WS Committer, Axis PMC Member Block time defines the time it takes to mine a block. Both in bitcoin blockchain and ethereum blockchain, there is an expected block time, and an average block time. In bitcoin, the expected block time is 10 minutes, while in ethereum it is between 10 to 19 seconds. Both bitcoin and ethereum, at the time of this writing use a proof of work based distributed consensus algorithm (ethereum is planned to move to a proof of stake based algorithm with its serenity release). The expected block time is set at a constant value to make sure, miners cannot impact the security of the network by adding more computational power. The average block time of the network is evaluated after n number of blocks, and if it is great than the expected block time, then the difficulty level of the proof of work algorithm will be reduced, and if it is less than the expected block time then the difficulty level will be increased. Thats the core design principle behind block time, but you will see as we proceed, how bitcoin and ethereum differentiate themselves from each other. The level of difficulty varies with the time, as per the following formula. It tries to evaluate the speed of the mining network and find out how much it deviates from the expected level. The expectation is to mine a block in 10 minutes. For example, if the average speed of mining the last 2016 blocks is 8 minutes then the new difficulty factor will be greater than one, so the current difficulty level will be increased. In case the average is above 10 minutes, then the factor will be less than 1 and the difficulty level will be decreased for the next 2016 blocks. The d Continue reading >>
Bitcoin Block Explorer - Blockchain
Like paper money and gold before it, bitcoin and ether allow parties to exchange value. Unlike their predecessors, they are digital and decentralized. For the first time in history, people can exchange value without intermediaries which translates to greater control of funds and lower fees. Search You may enter a block height, address, block hash, transaction hash, hash160, or ipv4 address... Continue reading >>
What Is The Block Size Limit
If you've been in crypto for a while, you've heard of the block size and the everlasting debate that surrounds it. This debate has plagued the community for years and it has pretty much torn it apart into two groups: Those in favor of a blocksize increase and those against it. But maybe you haven't been around long enough to know what the block size and the block size limit mean and why it's so heavily debated in the crypto sphere. The block size issue is much more than just a curiosity or technicality and it could indeed define the future of Bitcoin as a mainstream currency. So, what is the block size and why does it matter? Why are there groups that defend the block size limit while others push for an immediate increase? As you most likely know, Bitcoin is a blockchain-based cryptocurrency. All the transactions that take place within the network are recorded on this blockchain, a public ledger that can be seen by anyone but changed by no one. This ledger is made up of blocks that fit together cryptographically (hence the name, blockchain). When a user makes a transaction, said transaction is included in the block that is being mined at the time, and will later be confirmed by the blocks that follow it. The more blocks there are on top of your transaction, the safer it is to assume it is immutable. Transactions, at its most basic level, are made up of data which is usually composed of the information regarding the transaction itself. This data, like any other, takes up space on the block it is included. Currently, each block on the Bitcoin blockchain is able to contain 1mb of data, meaning that the block size of bitcoin is 1 megabyte. This means that there is a limit to how many transactions can fit in Bitcoin's blocks, according to the data contained in said transact Continue reading >>
Transactions - What Is A Block? - Bitcoin Stack Exchange
I know bitcoin has a block chain that is from my best representation a list of blocks. I know the block holds many transactions. But i'm still very much lost as to what a block is and how a block can be the function of the transactions at the time prior to the block being solved and how a block can have any number of transactions prior to it being solved and locked in. I'm also lost on the process of "solving" a block. I know it requires computers encrypting the transaction. If a block is multiple transaction would that imply that you have to solve all the transactions to get the block. possible duplicate of bitcoin.stackexchange.com/questions/7330/ Nick ODell Jan 23 '15 at 20:06 @NickODell, similar, but I think this one is more about the structure of a block, and the other how to build it given the state of the block chain. StephenM347 Jan 23 '15 at 22:51 There are a lot of questions on the Bitcoin SE about blocks, but remarkably I couldn't find any that explicitly lay out what a block is. A blocks has two things: A block header and a list of transactions. The version number is a parameter to help in updating how blocks are treated by the network. The reference to the hash of the previous block is what makes the group of blocks a "block chain". The merkle root is hash that can be used to prove that a transaction is in the block without providing all of the details of the block (this is a bit complicated, see this for more info). The time field is to show the network what time the block was solved at, and to help in calculating the difficulty parameter. The difficulty (or nBits as it is called in the code) is shorthand for how difficult it is to solve the block. Essentially, it encodes a target value, and the hash of the block (when treated as a 256 bit integer) must b Continue reading >>
The Reason Why Bitcoin Miners Dedicate Time To Mining Empty Blocks
The Reason Why Bitcoin Miners Dedicate Time to Mining Empty Blocks Bitcoin mining is an intriguing subject that can sometimes be overwhelming to understand at first without some research. One particular subject concerning the topic of mining is empty blocks, and people often wonder why mining pools mine them. Also read: Class Action Lawsuit Filed Against Cryptocurrency Exchange Kraken Mining pools are groups of bitcoin miners that work together to find and verify blocks roughly every ten minutes. Most of the time blocks are filled with transactions that are waiting to be confirmed as soon as the miner finds a specific block. Miners are rewarded 12.5 BTC and all the fees associated with the particular block they find. In the early days, blocks were not that full because bitcoin wasnt as popular as it is today. Latelyblocks have been full, often to the maximum size of 1 MB. Blocks filled with transactions are not the only blocks mined on the network as empty blocks are mined as well. Empty blocks actually do have a transaction in them called the coinbase which is included first in every block. The main reason why pools mine empty blocks is because they are performing operations non-stop. Now the biggest qualm people have with miners who dedicate energy to mining an empty block is due to the recent throughput congestion these days. Bitcoin mining is a non-stop race to find blocks. When miners win a race by finding a block they have also prepped up for the next race and begin competing almost instantly again. However, when a pool solves a block, it has to download it and perform a few functions in order for it to verify the contained transactions. At the same time, the pool is also receiving the next broadcasted header (80 bytes of data tethered to a block), and the pool b Continue reading >>