Skip to main content

How Bitcoin Mining Works

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.

How does mining take place?

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.

Making a hash of it

how bitcoin mining worksThis 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 of data like a bitcoin block, but it’s practically impossible to work out what the data was just by looking at the hash. And while it is very easy to produce a hash from a large amount of data, each hash is unique. If you change just one character in a bitcoin block, its hash will change completely.
Miners don’t just use the transactions in a block to generate a hash. Some other pieces of data are used too. One of these pieces of data is the hash of the last block stored in the blockchain.
Because each block’s hash is produced using the hash of the block before it, it becomes a digital version of a wax seal. It confirms that this block – and every block after it – is legitimate, because if you tampered with it, everyone would know.
If you tried to fake a transaction by changing a block that had already been stored in the blockchain, that block’s hash would change. If someone checked the block’s authenticity by running the hashing function on it, they’d find that the hash was different from the one already stored along with that block in the blockchain. The block would be instantly spotted as a fake.
Because each block’s hash is used to help produce the hash of the next block in the chain, tampering with a block would also make the subsequent block’s hash wrong too. That would continue all the way down the chain, throwing everything out of whack.

Competing for coins

Butterfly Labs Bitforce mining rigSo, that’s how miners ‘seal off’ a block. They all compete with each other to do this, using software written specifically to mine blocks. Every time someone successfully creates a hash, they get a reward of 25 bitcoins, the blockchain is updated, and everyone on the network hears about it. That’s the incentive to keep mining, and keep the transactions working.
The problem is that it’s very easy to produce a hash from a collection of data. Computers are really good at this. The bitcoin network has to make it more difficult, otherwise everyone would be hashing hundreds of transaction blocks each second, and all of the bitcoins would be mined in minutes. The bitcoin protocol deliberately makes it more difficult, by introducing something called ‘proof of work’.
The bitcoin protocol won’t just accept any old hash. It demands that a block’s hash has to look a certain way; it must have a certain number of zeroes at the start. There’s no way of telling what a hash is going to look like before you produce it, and as soon as you include a new piece of data in the mix, the hash will be totally different.
Miners aren’t supposed to meddle with the transaction data in a block, but they must change the data they’re using to create a different hash. They do this using another, random piece of data called a ‘nonce’. This is used with the transaction data to create a hash. If the hash doesn’t fit the required format, the nonce is changed, and the whole thing is hashed again. It can take many attempts to find a nonce that works, and all the miners in the network are trying to do it at the same time. That’s how miners earn their bitcoins.

Comments

Popular posts from this blog

Case-By-Case or Cease-and-Desist? In Search Of a New Approach to ICOs

That rumble you hear is the sound of regulators around the world mobilizing resources to tackle the pressing matter of token sales. Yet, in spite of the spectacular growth of blockchain token-based funding, no one seems to have a clear idea of what type of rules to introduce. The resulting uncertainty (not to mention ridicule) is left hindering progress as money flows to unviable projects and investors are left vulnerable to foul play – exactly what regulation is supposed to prevent. Perhaps a new approach is needed. But to see where this could go, it's worth stepping back and asking what we expect the regulation to do. Safety belt First, why do we need regulation, not just of finance, but of anything at all? To protect us. At its roots, that is the main role of government – to protect its citizens from avoidable harm and extreme loss brought about by others or from our own lack of common sense. When it comes to securities, that usually means stopping us from making poor decisions…

Duncan Logan just tweeted that he's on board Electroneum

I have been a buyer and holder of bitcoin and Etherreum for a long time but this will be the first ICO I buy into--Duncan Logan.

What is Electroneum?

Electroneum (ETN) is a cryptocurrency that can be mined with a smartphone, requiring almost no technical knowledge or prior experience. This sets it apart from other cryptocurrencies (like Bitcoin) which require expensive hardware and technical know-how to mine.
Electroneum’s unique mobile mining experience allows anyone with a smartphone to earn ETN coins by letting the miner app run in the background.
It was designed specifically with mobile users in mind, thereby appealing to a potential market of 2.2 billion smartphone users around the world. Unlike other cryptocurrencies, Electroneum has a user-friendly, beginner-oriented interface that allows users to seamlessly transfer ETN coins between one another, check their balances, and mine coins.
Being a cryptocurrency, Electroneum is created, held, and spent electronically, and has no phy…

Inglourious Basterds Script - Dialogue Transcript

oila! Finally, the Inglourious Basterds script is here for all you fans of the Quentin Tarantino movie. This puppy is a transcript that was painstakingly transcribed using the screenplay and/or viewings of the movie to get the dialogue.

Inglourious Basterds Script(DISTANT RUMBLING) (SPEAKING FRENCH) (MEN SPEAKING GERMAN) (SPEAKING FRENCH) While I'm very familiar with you and your family, I have no way of knowing if you are familiar with who I am. Are you aware of my existence? Yes. This is good. Now, are you aware of the job I've been ordered to carry out in France? Yes. Please tell me what you've heard. I've heard that the Führer has put you in charge of rounding up the Jews left in France who are either hiding or passing for Gentile. The Führer couldn't have said it better himself. But the meaning of your visit, pleasant though it is, is mysterious to me. The Germans looked through my house…