Cryptocurrency mining is painstaking, costly, and only sporadically rewarding. Nonetheless, mining has a magnetic appeal for many investors interested in cryptocurrency because of the fact that miners are rewarded for their work with crypto tokens. This may be because entrepreneurial types see mining as pennies from heaven, like California gold prospectors in 1849. And if you are technologically inclined, why not do it?
- By mining, you can earn cryptocurrency without having to put down money for it.
- Bitcoin miners receive Bitcoin as a reward for completing “blocks” of verified transactions which are added to the blockchain.
- Mining rewards are paid to the miner who discovers a solution to a complex hashing puzzle first, and the probability that a participant will be the one to discover the solution is related to the portion of the total mining power on the network.
- You need either a GPU (graphics processing unit) or an application-specific integrated circuit (ASIC) in order to set up a mining rig.
However, before you invest the time and equipment, read this explainer to see whether mining is really for you. We will focus primarily on Bitcoin (throughout, we’ll use “Bitcoin” when referring to the network or the cryptocurrency as a concept, and “bitcoin” when we’re referring to a quantity of individual tokens).
The primary draw for many mining is the prospect of being rewarded with Bitcoin. That said, you certainly don’t have to be a miner to own cryptocurrency tokens. You can also buy cryptocurrencies using fiat currency; you can trade it on an exchange like Bitstamp using another crypto (as an example, using Ethereum or NEO to buy Bitcoin); you even can earn it by shopping, publishing blog posts on platforms that pay users in cryptocurrency, or even set up interest-earning crypto accounts.
The Bitcoin reward that miners receive is an incentive that motivates people to assist in the primary purpose of mining: to legitimize and monitor Bitcoin transactions, ensuring their validity. Because these responsibilities are spread among many users all over the world, Bitcoin is a “decentralized” cryptocurrency, or one that does not rely on any central authority like a central bank or government to oversee its regulation.
How To Mine Bitcoins
Miners are getting paid for their work as auditors. They are doing the work of verifying the legitimacy of Bitcoin transactions. This convention is meant to keep Bitcoin users honest and was conceived by bitcoin’s founder, Satoshi Nakamoto. By verifying transactions, miners are helping to prevent the “double-spending problem.”
Double spending is a scenario in which a bitcoin owner illicitly spends the same bitcoin twice. With physical currency, this isn’t an issue: once you hand someone a $20 bill to buy a bottle of vodka, you no longer have it, so there’s no danger you could use that same $20 bill to buy lotto tickets next door. While there is the possibility of counterfeit cash being made, it is not exactly the same as literally spending the same dollar twice. With digital currency, however, as the Investopedia dictionary explains, “there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original.”
Let’s say you had one legitimate $20 bill and one counterfeit of that same $20. If you were to try to spend both the real bill and the fake one, someone that took the trouble of looking at both of the bills’ serial numbers would see that they were the same number, and thus one of them had to be false. What a Bitcoin miner does is analogous to that—they check transactions to make sure that users have not illegitimately tried to spend the same bitcoin twice. This isn’t a perfect analogy—we’ll explain in more detail below.
Once miners have verified 1 MB (megabyte) worth of bitcoin transactions, known as a “block,” those miners are eligible to be rewarded with a quantity of bitcoin (more about the bitcoin reward below as well). The 1 MB limit was set by Satoshi Nakamoto, and is a matter of controversy, as some miners believe the block size should be increased to accommodate more data, which would effectively mean that the bitcoin network could process and verify transactions more quickly.
Note that verifying 1 MB worth of transactions makes a coin miner eligible to earn bitcoin—not everyone who verifies transactions will get paid out.
1MB of transactions can theoretically be as small as one transaction (though this is not at all common) or several thousand. It depends on how much data the transactions take up.
“So after all that work of verifying transactions, I might still not get any bitcoin for it?”
That is correct.
To earn bitcoins, you need to meet two conditions. One is a matter of effort; one is a matter of luck.
1) You have to verify ~1MB worth of transactions. This is the easy part.
2) You have to be the first miner to arrive at the right answer, or closest answer, to a numeric problem. This process is also known as proof of work.
“What do you mean, ‘the right answer to a numeric problem’?”
The good news: No advanced math or computation is involved. You may have heard that miners are solving difficult mathematical problems—that’s not exactly true. What they’re actually doing is trying to be the first miner to come up with a 64-digit hexadecimal number (a “hash”) that is less than or equal to the target hash. It’s basically guesswork.
The bad news: It’s guesswork, but with the total number of possible guesses for each of these problems being on the order of trillions, it’s incredibly arduous work. In order to solve a problem first, miners need a lot of computing power. To mine successfully, you need to have a high “hash rate,” which is measured in terms of megahashes per second (MH/s), gigahashes per second (GH/s), and terahashes per second (TH/s).
The “Explain It Like I’m Five” Version
The ins and outs of bitcoin mining can be difficult to understand as is. Consider this illustrative example of how the hash problem works: I tell three friends that I’m thinking of a number between one and 100, and I write that number on a piece of paper and seal it in an envelope. My friends don’t have to guess the exact number; they just have to be the first person to guess any number that is less than or equal to the number I am thinking of. And there is no limit to how many guesses they get.
Let’s say I’m thinking of the number 19. If Friend A guesses 21, they lose because of 21>19. If Friend B guesses 16 and Friend C guesses 12, then they’ve both theoretically arrived at viable answers, because of 16<19 and 12<19. There is no “extra credit” for Friend B, even though B’s answer was closer to the target answer of 19. Now imagine that I pose the “guess what number I’m thinking of” question, but I’m not asking just three friends, and I’m not thinking of a number between 1 and 100. Rather, I’m asking millions of would-be miners and I’m thinking of a 64-digit hexadecimal number. Now you see that it’s going to be extremely hard to guess the right answer.
If B and C both answer simultaneously, then the ELI5 analogy breaks down.
In Bitcoin terms, simultaneous answers occur frequently, but at the end of the day, there can only be one winning answer. When multiple simultaneous answers are presented that are equal to or less than the target number, the Bitcoin network will decide by a simple majority—51%—which miner to honor. Typically, it is the miner who has done the most work or, in other words, the one that verifies the most transactions. The losing block then becomes an “orphan block.” Orphan blocks are those that are not added to the blockchain. Miners who successfully solve the hash problem but who haven’t verified the most transactions are not rewarded with bitcoin.
Is Bitcoin Mining Legal?
The legality of Bitcoin mining depends entirely on your geographic location. The concept of Bitcoin can threaten the dominance of fiat currencies and government control over the financial markets. For this reason, Bitcoin is completely illegal in certain places.
Bitcoin ownership and mining are legal in more countries than not. Some examples of places where it is illegal are Algeria, Egypt, Morocco, Bolivia, Ecuador, Nepal, and Pakistan.4 Overall, Bitcoin use and mining are legal across much of the globe.