Bitcoin's most important characteristic is that it is decentralized. No single institution controls the bitcoin network. It is maintained by a group of volunteer coders, and run by an open network of dedicated computers spread around the world. This attracts individuals and groups that are uncomfortable with the control that banks or government institutions have over their money.
While there is certainly the possibility of making short-term profits in Bitcoin, many market participants are viewing an investment in Bitcoin as a long-term play. If the cryptocurrency were to eventually become a favored form of global payment and remittance, there is no telling just how high prices could go. Some have even suggested that the price of Bitcoin could hit $50,000 in 2018 and eventually $1 million.
The primary purpose of mining is to allow Bitcoin nodes to reach a secure, tamper-resistant consensus. Mining is also the mechanism used to introduce bitcoins into the system. Miners are paid transaction fees as well as a subsidy of newly created coins, called block rewards. This both serves the purpose of disseminating new coins in a decentralized manner as well as motivating people to provide security for the system through mining.
Electricity cost: How many dollars are you paying per kilowatt? You’ll need to find out your electricity rate in order to calculate profitability. This can usually be found on your monthly electricity bill. The reason this is important is that miners consume electricity, whether for powering up the miner or for cooling it down (these machines can get really hot).
Let’s say a hacker wanted to change a transaction that happened 60 minutes, or six blocks, ago—maybe to remove evidence that she had spent some bitcoins, so she could spend them again. Her first step would be to go in and change the record for that transaction. Then, because she had modified the block, she would have to solve a new proof-of-work problem—find a new nonce—and do all of that computational work, all over again. (Again, due to the unpredictable nature of hash functions, making the slightest change to the original block means starting the proof of work from scratch.) From there, she’d have to start building an alternative chain going forward, solving a new proof-of-work problem for each block until she caught up with the present.
The use of bitcoin by criminals has attracted the attention of financial regulators, legislative bodies, law enforcement, and the media. In the United States, the FBI prepared an intelligence assessment, the SEC issued a pointed warning about investment schemes using virtual currencies, and the U.S. Senate held a hearing on virtual currencies in November 2013. The U.S. government claimed that bitcoin was used to facilitate payments related to Russian interference in the 2016 United States elections.
Difficulty increase per year: This is probably the most important and elusive variable of them all. The idea is that since no one can actually predict the rate of miners joining the network, neither can anyone predict how difficult it will be to mine in six weeks, six months, or six years from now. In fact, in all the time Bitcoin has existed, its profitability has dropped only a handful of times—even at times when the price was relatively low.
The difficulty is the measure of how difficult it is to find a new block compared to the easiest it can ever be. The rate is recalculated every 2,016 blocks to a value such that the previous 2,016 blocks would have been generated in exactly one fortnight (two weeks) had everyone been mining at this difficulty. This is expected yield, on average, one block every ten minutes.
The best mining sites were the old fruit warehouses—the basin is as famous for its apples as for its megawatts—but those got snapped up early. So Miehe, a tall, gregarious 38-year-old who would go on to set up a string of mines here, learned to look for less obvious solutions. He would roam the side streets and back roads, scanning for defunct businesses that might have once used a lot of power. An old machine shop, say. A closed-down convenience store. Or this: Miehe slows the Land Rover and points to a shuttered carwash sitting forlornly next to a Taco Bell. It has the space, he says. And with the water pumps and heaters, “there’s probably a ton of power distributed not very far from here,” Miehe tells me. “That could be a bitcoin mine.”
A wallet stores the information necessary to transact bitcoins. While wallets are often described as a place to hold or store bitcoins, due to the nature of the system, bitcoins are inseparable from the blockchain transaction ledger. A better way to describe a wallet is something that "stores the digital credentials for your bitcoin holdings" and allows one to access (and spend) them. Bitcoin uses public-key cryptography, in which two cryptographic keys, one public and one private, are generated. At its most basic, a wallet is a collection of these keys.
Because it's similar to gold mining in that the bitcoins exist in the protocol's design (just as the gold exists underground), but they haven't been brought out into the light yet (just as the gold hasn't yet been dug up). The bitcoin protocol stipulates that 21 million bitcoins will exist at some point. What "miners" do is bring them out into the light, a few at a time.
In January 2009, the bitcoin network was created when Nakamoto mined the first block of the chain, known as the genesis block. Embedded in the coinbase of this block was the following text: "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks." This note has been interpreted as both a timestamp and a comment on the instability caused by fractional-reserve banking.:18