How Ethereum Mining Works
With Ethereum, the world’s second-largest cryptocurrency by market capitalization, participants known as “miners” use expensive hardware to run calculations in an effort to earn rewards. By doing this, they mint Ethereum tokens, known as ether, at a steady pace.
Cryptocurrency mining was invented by Bitcoin creator Satoshi Nakamoto, a figure shrouded in mystery – no one knows their real identity. Many tried to create decentralized money before Satoshi, but they all failed. Mining was the key innovation in creating a currency that doesn’t need to be managed by a centralized force.
Ethereum copied this technique in pursuit of its own mission of decentralizing the internet and building decentralized apps that don’t have central entities that manage the service and can stop users from doing what they want.
Before exploring how Ethereum mining works, it’s important to understand why mining exists at all. There are a couple of key reasons:
To mint ether without a central issuer: Ethereum’s tokens, ether, are used to pay for apps on the network and are created through the process of mining at a rate of five ether roughly every 13 seconds.
To keep the network working correctly: Without mining, tokens could be double-spent by nefarious actors, which would devalue or even destroy the entire network.
Mining ether
Approximately every 12-15 seconds, an Ethereum miner finds a block. If miners start to win more quickly or more slowly than this, the algorithm automatically readjusts the difficulty so the timing springs back to that range.
The miners “win” these ether by mining them. Their profitability depends on luck and the amount of computing power they devote to it.
Keep the Ethereum working correctly`
The second point is important. Usually, banks are in charge of keeping accurate records of digital transactions. They ensure that money isn’t created out of thin air, and that users don’t cheat and spend their money more than once.
Blockchains such as Ethereum, with the help of mining, use a new way of record-keeping, one where a network of global users, rather than an intermediary, verifies transactions and adds them to the public ledger.
Although a “trustless” or “trust-minimizing” monetary system is the goal, someone still needs to secure the financial records, ensuring that no one cheats.
Mining is the key innovation that makes decentralized record-keeping possible.
How Ethereum mining works
Ethereum’s current mining process is almost the same as bitcoin’s.
For each block of transactions, miners use computers to repeatedly and very quickly produce random values until one of them stumbles upon the correct one. The correct answer unlocks the ether.
It’s very (very) difficult for miners to cheat at this game. There’s a less than microscopic chance that a miner can fake this work and come away with the correct answer. That’s why the puzzle-solving method, also called the “consensus mechanism,” is called “proof-of-work.”
“Nodes” are another important piece of the Ethereum network, each of which contains a copy of the ledger that records all ether transactions. There are thousands of Ethereum nodes throughout the world, maintained by companies or enthusiasts for the purposes of validating transactions. Each of these nodes verifies every block that a miner creates.
It takes just a second for nodes on the Ethereum network to verify that the hash value is correct. If it isn’t, they reject the miner’s block.
If the miner finds a hash that matches the current target, the miner unlocks the ether and broadcasts the block across the network for each node to validate and add to their own copy of the ledger. If miner A finds the hash, miner B will stop work on the current block and start the computational process over again for the next block.
Ethereum's shift to proof-of-stake
Ethereum might not need miners forever, though.
Ethereum developers have long planned to drop mining in favor of a different method of verifying transactions called proof-of-stake, which helps the network reach consensus about whether transactions are valid in a different way. The hope is that proof-of-stake would require less electricity than proof-of-work, making it a greener alternative.
The shift to proof-of-stake is part of the ongoing Ethereum 2.0 upgrade to Ethereum, but it will take time to implement. However, some blockchain experts are skeptical proof-of-stake can work and will be as resistant to attacks as proof-of-work.
Ethereum mining FAQ
Is Ethereum mining profitable?
The answer is complex. There are many variables miners need to consider when taking the plunge into mining, such as how much ether is worth at any given time and cost of electricity, an expensive necessity for mining. Not to mention, the cost of electricity varies across the globe.
To be profitable, most Ethereum miners join mining pools – groups of miners – which give miners a better chance of winning ether.Another pressing factor is that when the Ethereum 2.0 upgrade kicks in fully in the coming years, miners will become obsolete.
How decentralized is Ethereum mining?
Much of the Ethereum mining power is concentrated in the hands of just a few mining pools. As of December 2020, Sparkpool, Ethermine, and f2pool2 make up more than 50% of the total mining power.
The situation is similar for Bitcoin and other popular cryptocurrencies.
How do you mine Ethereum?
In short: Buy the equipment that is powerful enough and join a mining pool. Our guide goes into more detail.
Is Ethereum mining different from Bitcoin's?
The specific algorithm that ethereum uses is called “ethash,” designed to require more memory to make it harder to mine using expensive ASICs – specialized mining chips that are now the only profitable way of mining bitcoin. Despite this effort, Ethereum ASICs do exist.