Bitcoin mining seems crazy!
Computers mining for virtual coins? Is Bitcoin mining just free money?
Well, it's much, much more than that!
If you want the full explanation on Bitcoin mining, keep reading...
What is Bitcoin Mining?
Bitcoin mining is the backbone of the Bitcoin network.
Miners provide security and confirm Bitcoin transactions.
Without Bitcoin miners, the network would be attacked and dysfunctional.
Bitcoin mining is done by specialized computers.
The role of miners is to secure the network and to process every Bitcoin transaction.
Miners achieve this by solving a computational problem which allows them to chain together blocks of transactions (hence Bitcoin’s famous “blockchain”).
For this service, miners are rewarded with newly-created Bitcoins and transaction fees.
How Does Bitcoin Mining Work?
What is Bitcoin mining actually doing?
Miners are securing the network and confirming Bitcoin transactions.
Miners are paid rewards for their service every 10 minutes in the form of new bitcoins.
What is Bitcoin Mining Actually Doing?
What is the point of Bitcoin mining? This is something we're asked everyday!
There are many aspects and functions of Bitcoin mining and we'll go over them here. They are:
- Issuance of new bitcoins
- Confirming transactions
Mining Is Used to Issue new Bitcoins
Traditional currencies--like the dollar or euro--are issued by central banks. The central bank can issue new units of money ay anytime based on what they think will improve the economy.
Bitcoin is different.
With Bitcoin, miners are rewarded new bitcoins every 10 minutes.
The issuance rate is set in the code, so miners cannot cheat the system or create bitcoins out of thin air. They have to use their computing power to generate the new bitcoins.
Miners Confirm Transactions
Miners include transactions sent on the Bitcoin network in their blocks.
A transaction can only be considered secure and complete once it is included in a block.
Because only a when a transaction has been included in a block is it officially embedded into Bitcoin's blockchain.
More confirmations are better for larger payments. Here is a visual so you have a better idea:
Miners Secure the Network
Miners secure the Bitcoin network by making it difficult to attack, alter or stop.
The more miners that mine, the more the secure the network.
The only way to reverse Bitcoin transactions is to have more than 51% of the network hash power. Distributed hash power spread among many different miners keeps Bitcoin secure and safe.
How to Mine Bitcoins
Actually want to try mining bitcoins?
Well, you can do it. However, it's not profitable for most people as mining is a highly specialized industry.
Most Bitcoin mining is done in large warehouses where there is cheap electricity.
To be real:
Most people should NOT mine bitcoins today.
Most Bitcoin mining is specialized and the warehouses look something like this:
That's who you're up against! It’s simply too expensive and you are unlikely to turn a profit.
For hobby mining, we’ll show you some steps you can take to get started mining bitcoins right now.
Step #1: Get Bitcoin Mining Hardware
You won’t be able to mine without an ASIC miner.
ASIC miners are specialized computers that were built for the sole purpose of mining bitcoins.
Don’t even try mining bitcoins on your home desktop or laptop computer! You will earn less than one penny per year and will waste money on electricity.
Step #2: Select a Mining Pool
Once you get your mining hardware, you need to select a mining pool.
Without a mining pool, you would only receive a mining payout if you found a block on your own. This is called solo mining.
We don’t recommend this because your hardware’s hash rate is very unlikely to be anywhere near enough to find a block solo mining.
How do mining pools help?
By joining a mining pool you share your hash rate with the pool. Once the pool finds a block you get a payout based on the percent of hash rate contributed to the pool.
If you contributed 1% of the pools hashrate, you’d get .125 bitcoins out of the current 12.5 bitcoin block reward.
Step #3: Get Bitcoin Mining Software
Bitcoin mining software is how you actually hook your mining hardware into your desired mining pool.
You need to use the software to point your hash rate at the pool.
Also in the software you tell the pool which Bitcoin address payouts should be sent to.
If you don’t have a Bitcoin wallet or address learn how to get one here.
There is mining software available for Mac, Windows, and Linux.
Step #4: Is Bitcoin Mining Legal in your Country? Make Sure!
This won’t be much of an issue in MOST countries.
Consult local counsel for further assistance in determining whether Bitcoin mining is legal and the tax implications of doing the activity.
Step #5: Is Bitcoin Mining Profitable for You?
Do you understand what you need to do to start?
You should run some calculations and see if Bitcoin mining will actually be profitable for you.
You can use a Bitcoin mining calculator to get a rough idea.
I say rough idea because many factors related to your mining profitability are constantly changing.
A doubling in the Bitcoin price could increase your profits by two.
It could also make mining that much more competitive that your profits remain the same.
How to Mine Bitcoins on Android or iOS
Here’s what’s funny:
You actually CAN mine bitcoins on any Android device.
What’s not so fun?
You’ll likely make less than one penny PER YEAR!
Android phones simply are not powerful enough to match the mining hardware used by serious operations.
So, it might be cool to setup a miner on your Android phone to see how it works. But don’t expect to make any money.
Do expect to waste a lot of your phone’s battery!
What is Bitcoin Mining Hardware
Bitcoin mining hardware (ASICs) are high specialized computers used to mine bitcoins.
The ASIC industry has become complex and competitive.
Mining hardware is now only located where there is cheap electricity.
When Satoshi released Bitcoin, he intended it to be mined on computer CPUs.
GPUs were surpassed in turn by ASICs (Application Specific Integrated Circuits).
Nowadays all serious Bitcoin mining is performed on ASICs, usually in thermally-regulated data-centres with access to low-cost electricity.
Economies of scale have thus led to the concentration of mining power into fewer hands than originally intended.
What Are Bitcoin Mining Pools?
Mining pools allow small miners to receive more frequent mining payouts.
By joining with other miners in a group, a pool allows miners to find blocks more frequently.
But, there are some problems with mining pools as we'll discuss.
As with GPU and ASIC mining, Satoshi apparently failed to anticipate the emergence of mining pools.
Pools are groups of cooperating miners who agree to share block rewards in proportion to their contributed mining power.
This pie chart displays the current distribution of total mining power by pools:
While pools are desirable to the average miner as they smooth out rewards and make them more predictable, they unfortunately concentrate power to the mining pool’s owner.
Is Bitcoin Mining?
Isn’t Mining a Waste of Electricity?
Certain orthodox economists have criticized mining as wasteful.
It must be kept in mind however that this electricity is expended on useful work:
Enabling a monetary network worth billions (and potentially trillions) of dollars!
Compared to the carbon emissions from just the cars of PayPal’s employees as they commute to work, Bitcoin’s environmental impact is negligible.
As Bitcoin could easily replace PayPal, credit card companies, banks and the bureaucrats who regulate them all, it begs the question:
Isn’t traditional finance a waste?
Not just of electricity, but of money, time and human resources!
If only 21 million Bitcoins will ever be created, why has the issuance of Bitcoin not accelerated with the rising power of mining hardware?
Issuance is regulated by Difficulty, an algorithm which adjusts the difficulty of the Proof of Work problem in accordance with how quickly blocks are solved within a certain timeframe (roughly every 2 weeks or 2016 blocks).
Difficulty rises and falls with deployed hashing power to keep the average time between blocks at around 10 minutes.
Block Reward Halving
Satoshi designed Bitcoin such that the block reward, which miners automatically receive for solving a block, is halved every 210,000 blocks (or roughly 4 years).
As Bitcoin’s price has risen substantially (and is expected to keep rising over time), mining remains a profitable endeavor despite the falling block reward… at least for those miners on the bleeding edge of mining hardware with access to low-cost electricity.
Honest Miner Majority Secures the Network
To successfully attack the Bitcoin network by creating blocks with a falsified transaction record, a dishonest miner would require the majority of mining power so as to maintain the longest chain.
This is known as a 51% attack and it allows an attacker to spend the same coins multiple times and to blockade the transactions of other users at will.
To achieve it, an attacker needs to own mining hardware than all other honest miners.
This imposes a high monetary cost on any such attack.
At this stage of Bitcoin’s development, it’s likely that only major corporations or states would be able to meet this expense… although it’s unclear what net benefit, if any, such actors would gain from degrading or destroying Bitcoin.
Pools and specialized hardware has unfortunately led to a centralization trend in Bitcoin mining.
Bitcoin developer Greg Maxwell has stated that, to Bitcoin’s likely detriment, a handful of entities control the vast majority of hashing power.
It is also widely-known that at least 50% of mining hardware is located within China.
However, it’s may be argued that it’s contrary to the long-term economic interests of any miner to attempt such an attack.
The resultant fall in Bitcoin’s credibility would dramatically reduce its exchange rate, undermining the value of the miner’s hardware investment and their held coins.
As the community could then decide to reject the dishonest chain and revert to the last honest block, a 51% attack probably offers a poor risk-reward ratio to miners.
Bitcoin mining is certainly not perfect but possible improvements are always being suggested and considered.
How Does Bitcoin Mining Work?
This simplified illustration is helpful to explanation:
Let’s say the Green user wants to buy some goods from the Red user. Green sends 1 bitcoin to Red.
Green’s wallet announces a 1 bitcoin payment to Red’s wallet. This information, known as transaction (and sometimes abbreviated as “ tx”) is broadcast to as many Full Nodes as connect with Green’s wallet – typically 8. A full node is a special, transaction-relaying wallet which maintains a current copy of the entire blockchain.
Full Nodes then check Green’s spend against other pending transactions. If there are no conflicts (e.g. Green didn’t try to cheat by sending the exact same coins to Red and a third user), full nodes broadcast the transaction across the Bitcoin network. At this point, the transaction has not yet entered the Blockchain. Red would be taking a big risk by sending any goods to Green before the transaction is confirmed. So how do transactions get confirmed? This is where Miners enter the picture.
4) Processing by Miners
Miners, like full nodes, maintain a complete copy of the blockchain and monitor the network for newly-announced transactions. Green’s transaction may in fact reach a miner directly, without being relayed through a full node. In either case, a miner then performs work in an attempt to fit all new, valid transactions into the current block.
Miners race each other to complete the work, which is to “package” the current block so that it’s acceptable to the rest of the network. Acceptable blocks include a solution to a Proof of Work computational problem, known as ahash . The more computing power a miner controls, the higher their hashrate and the greater their odds of solving the current block.
But why do miners invest in expensive computing hardware and race each other to solve blocks? Because, as a reward for verifying and recording everyone’s transactions, miners receive a substantial Bitcoin reward for every solved block!
And what is a hash? Well, try entering all the characters in the above paragraph, from “But” to “block!” into this hashing utility. If you pasted correctly – as a string hash with no spaces after the exclamation mark – the SHA-256 algorithm used in Bitcoin should produce:
If the characters are altered even slightly, the result won’t match. So, a hash is a way to verify any amount of data is accurate. To solve a block, miners modify non-transaction data in the current block such that their hash result begins with a certain number (according to the current Difficulty, covered below) of zeroes. If you manually modify the string until you get a 0… result, you’ll soon see why this is considered “Proof of Work!”
5) Blockchain Confirmation
The first miner to solve the block containing Green’s payment to Red announces the newly-solved block to the network. If other full nodes agree the block is valid, the new block is added to the blockchain and the entire process begins afresh. Once recorded in the blockchain, Green’s payment goes from pending to confirmed status.
Red may now consider sending the goods to Green. However, the more new blocks are layered atop the one containing Green’s payment, the harder to reverse that transaction becomes. For significant sums of money, it’s recommended to wait for at least 6 confirmations. Given new blocks are produced on average every ten minutes; the wait shouldn’t take much longer than an hour.
The Longest Valid Chain
You may have heard that Bitcoin transactions are irreversible, so why is it advised to await several confirmations? The answer is somewhat complex and requires a solid understanding of the above mining process:
Let’s imagine two miners, A in China and B in Iceland, who solve the current block at roughly the same time. A’s block (A1) propagates through the internet from Beijing, reaching nodes in the East. B’s block (B1) is first to reach nodes in the West. There are now two competing versions of the blockchain!
Which blockchain prevails? Quite simply, the longest valid chain becomes the official version of events. So, let’s say the next miner to solve a block adds it to B’s chain, creating B2. If B2 propagates across the entire network before A2 is found, then B’s chain is the clear winner. A loses his mining reward and fees, which only exist on the invalidated A -chain.
Going back to the example of Green’s payment to Red, let’s say this transaction was included by A but rejected by B, who demands a higher fee than was included by Green. If B’s chain wins then Green’s transaction won’t appear in the B chain – it will be as if the funds never left Green’s wallet.
Although such blockchain splits are rare, they’re a credible risk. The more confirmations have passed, the safer a transaction is considered.